Add logbook entries, data export page, and JSON import

app.py

@@ -1,11 +1,15 @@
-from flask import Flask, render_template, redirect, url_for, request, flash, abort, send_from_directory, jsonify
+from flask import Flask, render_template, redirect, url_for, request, flash, abort, send_from_directory, jsonify, Response
 from sqlalchemy import create_engine, func
 from sqlalchemy.orm import scoped_session, sessionmaker
 
 from datetime import datetime, date, timedelta
+import csv
+import io
+import json
 import re
+import zipfile
 
-from models import Base, Battery, BatteryPctLog, Device, CapacityTest, ChargeLog
+from models import Base, Battery, BatteryPctLog, Device, CapacityTest, ChargeLog, Logbook
 
 
 def _parse_date(val: str) -> str | None:
@@ -231,7 +235,8 @@ def create_app(config_object="config"):
                                pct_logs=pct_logs,
                                charge_logs_data=charge_logs_data,
                                capacity_tests_data=capacity_tests_data,
-                               pct_logs_data=pct_logs_data)
+                               pct_logs_data=pct_logs_data,
+                               logbook_entries=battery.logbook_entries)
 
     # ------------------------------------------------------------------ #
     # Battery — edit notes
@@ -634,8 +639,10 @@ def create_app(config_object="config"):
         devices = db.query(Device).order_by(Device.name).all()
         device_types = sorted({d.device_type for d in devices if d.device_type})
         device_locations = sorted({d.location for d in devices if d.location})
+        device_battery_sizes = sorted({d.battery_size for d in devices if d.battery_size})
         return render_template("device_list.html", devices=devices,
-                               device_types=device_types, device_locations=device_locations)
+                               device_types=device_types, device_locations=device_locations,
+                               device_battery_sizes=device_battery_sizes)
 
     # ------------------------------------------------------------------ #
     # Devices — add
@@ -646,19 +653,31 @@ def create_app(config_object="config"):
         all_devices = db.query(Device).all()
         device_types = sorted({d.device_type for d in all_devices if d.device_type})
         device_locations = sorted({d.location for d in all_devices if d.location})
+        device_battery_sizes = sorted({d.battery_size for d in all_devices if d.battery_size})
 
         if request.method == "POST":
             name = request.form.get("name", "").strip()
             slots_raw = request.form.get("battery_slots", "1").strip()
             notes = request.form.get("notes", "").strip() or None
             device_type = request.form.get("device_type", "").strip() or None
+            battery_size = request.form.get("battery_size", "").strip() or None
             location = request.form.get("location", "").strip() or None
 
             if not name:
                 flash("Device name is required.", "error")
                 return render_template("device_add.html",
                                        device_types=device_types,
-                                       device_locations=device_locations), 400
+                                       device_locations=device_locations,
+                                       device_battery_sizes=device_battery_sizes), 400
+
+            if not battery_size:
+                flash("Battery size is required.", "error")
+                return render_template("device_add.html",
+                                       device_types=device_types,
+                                       device_locations=device_locations,
+                                       device_battery_sizes=device_battery_sizes,
+                                       form_name=name, form_notes=notes or "",
+                                       form_device_type=request.form.get("device_type", "")), 400
 
             try:
                 slots = int(slots_raw)
@@ -669,6 +688,7 @@ def create_app(config_object="config"):
                 return render_template("device_add.html",
                                        device_types=device_types,
                                        device_locations=device_locations,
+                                       device_battery_sizes=device_battery_sizes,
                                        form_name=name, form_notes=notes or "",
                                        form_device_type=request.form.get("device_type", "")), 400
 
@@ -677,19 +697,22 @@ def create_app(config_object="config"):
                 return render_template("device_add.html",
                                        device_types=device_types,
                                        device_locations=device_locations,
+                                       device_battery_sizes=device_battery_sizes,
                                        form_name=name, form_slots=slots,
                                        form_notes=notes or "",
                                        form_device_type=request.form.get("device_type", "")), 400
 
             device = Device(name=name, battery_slots=slots, notes=notes,
-                            device_type=device_type, location=location)
+                            device_type=device_type, battery_size=battery_size,
+                            location=location)
             db.add(device)
             db.commit()
             flash(f"Device '{name}' added.", "success")
             return redirect(url_for("device_list"))
 
         return render_template("device_add.html", device_types=device_types,
-                               device_locations=device_locations)
+                               device_locations=device_locations,
+                               device_battery_sizes=device_battery_sizes)
 
     # ------------------------------------------------------------------ #
     # Devices — detail
@@ -700,12 +723,22 @@ def create_app(config_object="config"):
         device = db.get(Device, device_id)
         if device is None:
             abort(404)
-        brands = [r[0] for r in db.query(Battery.brand).distinct().order_by(Battery.brand).all()]
+        all_devices = db.query(Device).all()
-        available_batteries = (db.query(Battery)
+        brands_q = db.query(Battery.brand).filter(Battery.status == "available")
-            .filter_by(status="available")
+        if device.battery_size:
-            .order_by(Battery.label).all())
+            brands_q = brands_q.filter(
-        device_types = sorted({d.device_type for d in db.query(Device).all() if d.device_type})
+                (Battery.size == device.battery_size) | (Battery.size == None)
-        device_locations = sorted({d.location for d in db.query(Device).all() if d.location})
+            )
+        brands = [r[0] for r in brands_q.distinct().order_by(Battery.brand).all()]
+        avail_q = db.query(Battery).filter_by(status="available")
+        if device.battery_size:
+            avail_q = avail_q.filter(
+                (Battery.size == device.battery_size) | (Battery.size == None)
+            )
+        available_batteries = avail_q.order_by(Battery.label).all()
+        device_types = sorted({d.device_type for d in all_devices if d.device_type})
+        device_locations = sorted({d.location for d in all_devices if d.location})
+        device_battery_sizes = sorted({d.battery_size for d in all_devices if d.battery_size})
         ha_live_pct = None
         if ha_client.enabled and device.ha_entity_id:
             ha_live_pct = ha_client.get_state(device.ha_entity_id, timeout=1)
@@ -727,8 +760,10 @@ def create_app(config_object="config"):
                                available_batteries=available_batteries,
                                device_types=device_types,
                                device_locations=device_locations,
+                               device_battery_sizes=device_battery_sizes,
                                ha_enabled=ha_client.enabled,
-                               ha_live_pct=ha_live_pct)
+                               ha_live_pct=ha_live_pct,
+                               logbook_entries=device.logbook_entries)
 
     # ------------------------------------------------------------------ #
     # Devices — edit
@@ -763,6 +798,9 @@ def create_app(config_object="config"):
         device.battery_slots = slots
         device.notes = notes
         device.device_type = device_type
+        new_battery_size = request.form.get("battery_size", "").strip() or None
+        if new_battery_size is not None:
+            device.battery_size = new_battery_size
         device.location = request.form.get("location", "").strip() or None
         device.ha_entity_id = request.form.get("ha_entity_id", "").strip() or None
         db.commit()
@@ -807,11 +845,12 @@ def create_app(config_object="config"):
 
         # Validate availability before writing anything
         for brand, qty in pairs:
-            available_count = (
+            avail_q = db.query(func.count(Battery.id)).filter_by(brand=brand, status="available")
-                db.query(func.count(Battery.id))
+            if device.battery_size:
-                .filter_by(brand=brand, status="available")
+                avail_q = avail_q.filter(
-                .scalar()
+                    (Battery.size == device.battery_size) | (Battery.size == None)
-            )
+                )
+            available_count = avail_q.scalar()
             if available_count < qty:
                 flash(
                     f"Need {qty} {brand}, but only {available_count} available.",
@@ -822,13 +861,12 @@ def create_app(config_object="config"):
         # All checks passed — perform installs
         total_installed = 0
         for brand, qty in pairs:
-            batch = (
+            batch_q = db.query(Battery).filter_by(brand=brand, status="available")
-                db.query(Battery)
+            if device.battery_size:
-                .filter_by(brand=brand, status="available")
+                batch_q = batch_q.filter(
-                .order_by(Battery.id)
+                    (Battery.size == device.battery_size) | (Battery.size == None)
-                .limit(qty)
+                )
-                .all()
+            batch = batch_q.order_by(Battery.id).limit(qty).all()
-            )
             for b in batch:
                 b.status = "installed"
                 b.device_id = device.id
@@ -870,6 +908,12 @@ def create_app(config_object="config"):
                 f"{', '.join(existing_brands)}. Mixing brands is not recommended.",
                 "warning",
             )
+        if device.battery_size and battery.size and battery.size != device.battery_size:
+            flash(
+                f"Warning: {device.name} requires {device.battery_size} batteries, "
+                f"but {battery.label} is {battery.size}.",
+                "warning",
+            )
         battery.status = "installed"
         battery.device_id = device.id
         db.commit()
@@ -916,6 +960,406 @@ def create_app(config_object="config"):
         )
         return redirect(url_for("device_list"))
 
+    # ------------------------------------------------------------------ #
+    # Export
+    # ------------------------------------------------------------------ #
+
+    def _batteries_csv():
+        rows = db.query(Battery).order_by(Battery.id).all()
+        buf = io.StringIO()
+        w = csv.writer(buf)
+        w.writerow(["id", "label", "brand", "status", "device_id", "device_name",
+                    "size", "chemistry", "capacity_mah", "tested_capacity_mah",
+                    "tested_date", "charge_cycles", "purchase_date",
+                    "storage_location", "battery_percentage", "notes"])
+        for b in rows:
+            w.writerow([b.id, b.label, b.brand, b.status, b.device_id or "",
+                        b.device.name if b.device else "",
+                        b.size or "", b.chemistry or "", b.capacity_mah or "",
+                        b.tested_capacity_mah or "", b.tested_date or "",
+                        b.charge_cycles or "", b.purchase_date or "",
+                        b.storage_location or "", b.battery_percentage or "", b.notes or ""])
+        return buf.getvalue()
+
+    def _devices_csv():
+        rows = db.query(Device).order_by(Device.id).all()
+        buf = io.StringIO()
+        w = csv.writer(buf)
+        w.writerow(["id", "name", "battery_slots", "installed_count",
+                    "device_type", "battery_size", "location", "ha_entity_id", "notes"])
+        for d in rows:
+            w.writerow([d.id, d.name, d.battery_slots, d.installed_count(),
+                        d.device_type or "", d.battery_size or "",
+                        d.location or "", d.ha_entity_id or "", d.notes or ""])
+        return buf.getvalue()
+
+    def _charge_logs_csv():
+        rows = db.query(ChargeLog).order_by(ChargeLog.id).all()
+        buf = io.StringIO()
+        w = csv.writer(buf)
+        w.writerow(["id", "battery_id", "battery_label", "charged_date", "increment_cycles", "notes"])
+        for l in rows:
+            w.writerow([l.id, l.battery_id, l.battery.label,
+                        l.charged_date, l.increment_cycles, l.notes or ""])
+        return buf.getvalue()
+
+    def _capacity_tests_csv():
+        rows = db.query(CapacityTest).order_by(CapacityTest.id).all()
+        buf = io.StringIO()
+        w = csv.writer(buf)
+        w.writerow(["id", "battery_id", "battery_label", "tested_capacity_mah", "tested_date", "notes"])
+        for t in rows:
+            w.writerow([t.id, t.battery_id, t.battery.label,
+                        t.tested_capacity_mah, t.tested_date, t.notes or ""])
+        return buf.getvalue()
+
+    def _pct_logs_csv():
+        rows = db.query(BatteryPctLog).order_by(BatteryPctLog.id).all()
+        buf = io.StringIO()
+        w = csv.writer(buf)
+        w.writerow(["id", "battery_id", "battery_label", "percentage", "recorded_at", "source"])
+        for l in rows:
+            w.writerow([l.id, l.battery_id, l.battery.label,
+                        l.percentage, l.recorded_at, l.source or ""])
+        return buf.getvalue()
+
+    @app.route("/export")
+    def export_page():
+        return render_template("export.html")
+
+    @app.route("/export/batteries.csv")
+    def export_batteries_csv():
+        return Response(_batteries_csv(), mimetype="text/csv",
+            headers={"Content-Disposition": "attachment; filename=batteries.csv"})
+
+    @app.route("/export/devices.csv")
+    def export_devices_csv():
+        return Response(_devices_csv(), mimetype="text/csv",
+            headers={"Content-Disposition": "attachment; filename=devices.csv"})
+
+    @app.route("/export/charge-logs.csv")
+    def export_charge_logs_csv():
+        return Response(_charge_logs_csv(), mimetype="text/csv",
+            headers={"Content-Disposition": "attachment; filename=charge-logs.csv"})
+
+    @app.route("/export/capacity-tests.csv")
+    def export_capacity_tests_csv():
+        return Response(_capacity_tests_csv(), mimetype="text/csv",
+            headers={"Content-Disposition": "attachment; filename=capacity-tests.csv"})
+
+    @app.route("/export/pct-logs.csv")
+    def export_pct_logs_csv():
+        return Response(_pct_logs_csv(), mimetype="text/csv",
+            headers={"Content-Disposition": "attachment; filename=pct-logs.csv"})
+
+    @app.route("/export/csv.zip")
+    def export_csv_zip():
+        zip_buf = io.BytesIO()
+        with zipfile.ZipFile(zip_buf, "w", compression=zipfile.ZIP_DEFLATED) as zf:
+            zf.writestr("batteries.csv",     _batteries_csv())
+            zf.writestr("devices.csv",        _devices_csv())
+            zf.writestr("charge-logs.csv",    _charge_logs_csv())
+            zf.writestr("capacity-tests.csv", _capacity_tests_csv())
+            zf.writestr("pct-logs.csv",       _pct_logs_csv())
+        zip_buf.seek(0)
+        fname = f"battery-tracker-{datetime.utcnow().strftime('%Y%m%d')}.zip"
+        return Response(zip_buf.read(), mimetype="application/zip",
+            headers={"Content-Disposition": f"attachment; filename={fname}"})
+
+    @app.route("/export/all.json")
+    def export_json():
+        batteries      = db.query(Battery).order_by(Battery.id).all()
+        devices        = db.query(Device).order_by(Device.id).all()
+        charge_logs    = db.query(ChargeLog).order_by(ChargeLog.id).all()
+        capacity_tests = db.query(CapacityTest).order_by(CapacityTest.id).all()
+        pct_logs       = db.query(BatteryPctLog).order_by(BatteryPctLog.id).all()
+        payload = {
+            "exported_at": datetime.utcnow().strftime("%Y-%m-%d %H:%M:%S"),
+            "batteries": [
+                {"id": b.id, "label": b.label, "brand": b.brand, "status": b.status,
+                 "device_id": b.device_id, "device_name": b.device.name if b.device else None,
+                 "size": b.size, "chemistry": b.chemistry, "capacity_mah": b.capacity_mah,
+                 "tested_capacity_mah": b.tested_capacity_mah, "tested_date": b.tested_date,
+                 "charge_cycles": b.charge_cycles, "purchase_date": b.purchase_date,
+                 "storage_location": b.storage_location,
+                 "battery_percentage": b.battery_percentage, "notes": b.notes}
+                for b in batteries
+            ],
+            "devices": [
+                {"id": d.id, "name": d.name, "battery_slots": d.battery_slots,
+                 "installed_count": d.installed_count(), "device_type": d.device_type,
+                 "battery_size": d.battery_size, "location": d.location,
+                 "ha_entity_id": d.ha_entity_id, "notes": d.notes}
+                for d in devices
+            ],
+            "charge_logs": [
+                {"id": l.id, "battery_id": l.battery_id, "battery_label": l.battery.label,
+                 "charged_date": l.charged_date, "increment_cycles": l.increment_cycles,
+                 "notes": l.notes}
+                for l in charge_logs
+            ],
+            "capacity_tests": [
+                {"id": t.id, "battery_id": t.battery_id, "battery_label": t.battery.label,
+                 "tested_capacity_mah": t.tested_capacity_mah, "tested_date": t.tested_date,
+                 "notes": t.notes}
+                for t in capacity_tests
+            ],
+            "pct_logs": [
+                {"id": l.id, "battery_id": l.battery_id, "battery_label": l.battery.label,
+                 "percentage": l.percentage, "recorded_at": l.recorded_at, "source": l.source}
+                for l in pct_logs
+            ],
+        }
+        return Response(json.dumps(payload, indent=2), mimetype="application/json",
+            headers={"Content-Disposition": "attachment; filename=battery-tracker-export.json"})
+
+    # ------------------------------------------------------------------ #
+    # Import
+    # ------------------------------------------------------------------ #
+
+    @app.route("/import", methods=["GET", "POST"])
+    def import_page():
+        if request.method == "GET":
+            return render_template("import.html", results=None)
+
+        # --- file presence ---
+        if "file" not in request.files or request.files["file"].filename == "":
+            flash("No file selected.", "error")
+            return render_template("import.html", results=None), 400
+
+        f = request.files["file"]
+
+        # --- size check (10 MB) ---
+        f.seek(0, 2)
+        size = f.tell()
+        f.seek(0)
+        if size > 10 * 1024 * 1024:
+            flash("File too large (max 10 MB).", "error")
+            return render_template("import.html", results=None), 400
+
+        # --- JSON parse ---
+        try:
+            data = json.load(f)
+        except (json.JSONDecodeError, UnicodeDecodeError) as e:
+            flash(f"Invalid JSON file: {e}", "error")
+            return render_template("import.html", results=None), 400
+
+        # --- key validation ---
+        if not isinstance(data, dict) or "batteries" not in data or "devices" not in data:
+            flash("Invalid format: JSON must contain 'batteries' and 'devices' keys.", "error")
+            return render_template("import.html", results=None), 400
+
+        device_id_map  = {}
+        battery_id_map = {}
+        devices_created = devices_skipped = 0
+        batteries_created = batteries_skipped = 0
+        charge_logs_appended = charge_logs_skipped = 0
+        capacity_tests_appended = capacity_tests_skipped = 0
+        pct_logs_appended = pct_logs_skipped = 0
+
+        try:
+            # --- devices ---
+            for d in data.get("devices", []):
+                old_id = d.get("id")
+                name   = (d.get("name") or "").strip()
+                if not name:
+                    devices_skipped += 1
+                    continue
+                existing = db.query(Device).filter_by(name=name).first()
+                if existing:
+                    if old_id is not None:
+                        device_id_map[old_id] = existing.id
+                    devices_skipped += 1
+                else:
+                    new_dev = Device(
+                        name          = name,
+                        battery_slots = d.get("battery_slots") or 1,
+                        device_type   = d.get("device_type") or None,
+                        battery_size  = d.get("battery_size") or "",
+                        location      = d.get("location") or None,
+                        ha_entity_id  = d.get("ha_entity_id") or None,
+                        notes         = d.get("notes") or None,
+                    )
+                    db.add(new_dev)
+                    db.flush()
+                    if old_id is not None:
+                        device_id_map[old_id] = new_dev.id
+                    devices_created += 1
+
+            # --- batteries ---
+            for b in data.get("batteries", []):
+                old_id = b.get("id")
+                label  = (b.get("label") or "").strip()
+                if not label:
+                    batteries_skipped += 1
+                    continue
+                existing = db.query(Battery).filter_by(label=label).first()
+                if existing:
+                    if old_id is not None:
+                        battery_id_map[old_id] = existing.id
+                    batteries_skipped += 1
+                else:
+                    old_device_id = b.get("device_id")
+                    new_device_id = device_id_map.get(old_device_id) if old_device_id is not None else None
+                    source_status = b.get("status", "available")
+                    if new_device_id is not None:
+                        status = "installed"
+                    elif source_status == "retired":
+                        status = "retired"
+                    else:
+                        status = "available"
+                    new_bat = Battery(
+                        label               = label,
+                        brand               = b.get("brand") or "Unknown",
+                        status              = status,
+                        device_id           = new_device_id,
+                        size                = b.get("size") or None,
+                        chemistry           = b.get("chemistry") or None,
+                        capacity_mah        = b.get("capacity_mah") or None,
+                        tested_capacity_mah = b.get("tested_capacity_mah") or None,
+                        tested_date         = b.get("tested_date") or None,
+                        charge_cycles       = b.get("charge_cycles") or None,
+                        purchase_date       = b.get("purchase_date") or None,
+                        storage_location    = b.get("storage_location") or None,
+                        battery_percentage  = b.get("battery_percentage") or None,
+                        notes               = b.get("notes") or None,
+                    )
+                    db.add(new_bat)
+                    db.flush()
+                    if old_id is not None:
+                        battery_id_map[old_id] = new_bat.id
+                    batteries_created += 1
+
+            # --- charge logs ---
+            for cl in data.get("charge_logs", []):
+                old_bat_id = cl.get("battery_id")
+                new_bat_id = battery_id_map.get(old_bat_id)
+                if new_bat_id is None:
+                    charge_logs_skipped += 1
+                    continue
+                db.add(ChargeLog(
+                    battery_id       = new_bat_id,
+                    charged_date     = cl.get("charged_date") or date.today().isoformat(),
+                    increment_cycles = cl.get("increment_cycles") or 0,
+                    notes            = cl.get("notes") or None,
+                ))
+                charge_logs_appended += 1
+
+            # --- capacity tests ---
+            for ct in data.get("capacity_tests", []):
+                old_bat_id = ct.get("battery_id")
+                new_bat_id = battery_id_map.get(old_bat_id)
+                if new_bat_id is None:
+                    capacity_tests_skipped += 1
+                    continue
+                db.add(CapacityTest(
+                    battery_id          = new_bat_id,
+                    tested_capacity_mah = ct.get("tested_capacity_mah") or 0,
+                    tested_date         = ct.get("tested_date") or date.today().isoformat(),
+                    notes               = ct.get("notes") or None,
+                ))
+                capacity_tests_appended += 1
+
+            # --- pct logs ---
+            for pl in data.get("pct_logs", []):
+                old_bat_id = pl.get("battery_id")
+                new_bat_id = battery_id_map.get(old_bat_id)
+                if new_bat_id is None:
+                    pct_logs_skipped += 1
+                    continue
+                db.add(BatteryPctLog(
+                    battery_id  = new_bat_id,
+                    percentage  = pl.get("percentage") or 0,
+                    recorded_at = pl.get("recorded_at") or datetime.utcnow().strftime("%Y-%m-%d %H:%M:%S"),
+                    source      = pl.get("source") or None,
+                ))
+                pct_logs_appended += 1
+
+            db.commit()
+
+        except Exception as e:
+            db.rollback()
+            flash(f"Import failed: {e}", "error")
+            return render_template("import.html", results=None), 500
+
+        flash(
+            f"Import complete: {devices_created} device(s) and {batteries_created} battery/ies created.",
+            "success",
+        )
+        results = {
+            "devices_created":          devices_created,
+            "devices_skipped":          devices_skipped,
+            "batteries_created":        batteries_created,
+            "batteries_skipped":        batteries_skipped,
+            "charge_logs_appended":     charge_logs_appended,
+            "charge_logs_skipped":      charge_logs_skipped,
+            "capacity_tests_appended":  capacity_tests_appended,
+            "capacity_tests_skipped":   capacity_tests_skipped,
+            "pct_logs_appended":        pct_logs_appended,
+            "pct_logs_skipped":         pct_logs_skipped,
+        }
+        return render_template("import.html", results=results)
+
+    # ------------------------------------------------------------------ #
+    # Logbook
+    # ------------------------------------------------------------------ #
+
+    @app.route("/battery/<int:battery_id>/logbook/add", methods=["POST"])
+    def battery_logbook_add(battery_id):
+        battery = db.get(Battery, battery_id)
+        if battery is None:
+            abort(404)
+        body = request.form.get("body", "").strip()
+        if not body:
+            flash("Entry text is required.", "error")
+        else:
+            battery.logbook_entries.append(
+                Logbook(body=body, recorded_at=datetime.utcnow().strftime("%Y-%m-%d %H:%M:%S"))
+            )
+            db.commit()
+            flash("Logbook entry added.", "success")
+        return redirect(url_for("battery_detail", battery_id=battery_id))
+
+    @app.route("/battery/<int:battery_id>/logbook/<int:entry_id>/delete", methods=["POST"])
+    def battery_logbook_delete(battery_id, entry_id):
+        battery = db.get(Battery, battery_id)
+        if battery is None:
+            abort(404)
+        entry = db.get(Logbook, entry_id)
+        if entry and entry in battery.logbook_entries:
+            battery.logbook_entries.remove(entry)
+            db.commit()
+            flash("Logbook entry deleted.", "success")
+        return redirect(url_for("battery_detail", battery_id=battery_id))
+
+    @app.route("/device/<int:device_id>/logbook/add", methods=["POST"])
+    def device_logbook_add(device_id):
+        device = db.get(Device, device_id)
+        if device is None:
+            abort(404)
+        body = request.form.get("body", "").strip()
+        if not body:
+            flash("Entry text is required.", "error")
+        else:
+            device.logbook_entries.append(
+                Logbook(body=body, recorded_at=datetime.utcnow().strftime("%Y-%m-%d %H:%M:%S"))
+            )
+            db.commit()
+            flash("Logbook entry added.", "success")
+        return redirect(url_for("device_detail", device_id=device_id))
+
+    @app.route("/device/<int:device_id>/logbook/<int:entry_id>/delete", methods=["POST"])
+    def device_logbook_delete(device_id, entry_id):
+        device = db.get(Device, device_id)
+        if device is None:
+            abort(404)
+        entry = db.get(Logbook, entry_id)
+        if entry and entry in device.logbook_entries:
+            device.logbook_entries.remove(entry)
+            db.commit()
+            flash("Logbook entry deleted.", "success")
+        return redirect(url_for("device_detail", device_id=device_id))
+
     return app
 
 

models.py

@@ -1,10 +1,25 @@
 from datetime import datetime
 
-from sqlalchemy import Column, Integer, String, Text, ForeignKey
+from sqlalchemy import Column, Integer, String, Text, ForeignKey, Table
 from sqlalchemy.orm import declarative_base, relationship
 
 Base = declarative_base()
 
+# Association tables for logbook (defined before ORM classes so they can be
+# referenced as `secondary` in relationship()). String-based FKs are resolved
+# lazily when create_all() binds the metadata.
+battery_logbook_table = Table(
+    "battery_logbook", Base.metadata,
+    Column("battery_id", Integer, ForeignKey("battery.id", ondelete="CASCADE"), primary_key=True),
+    Column("logbook_id", Integer, ForeignKey("logbook.id", ondelete="CASCADE"), primary_key=True),
+)
+
+device_logbook_table = Table(
+    "device_logbook", Base.metadata,
+    Column("device_id", Integer, ForeignKey("device.id", ondelete="CASCADE"), primary_key=True),
+    Column("logbook_id", Integer, ForeignKey("logbook.id", ondelete="CASCADE"), primary_key=True),
+)
+
 
 class Device(Base):
     __tablename__ = "device"
@@ -13,11 +28,18 @@ class Device(Base):
     name = Column(String(100), nullable=False, unique=True)
     battery_slots = Column(Integer, nullable=False, default=1)
     device_type   = Column(String(50),  nullable=True)
+    battery_size  = Column(String(20),  nullable=False)  # AA, AAA, 9V, CR2032 …
     location      = Column(String(100), nullable=True)
     notes = Column(Text, nullable=True)
     ha_entity_id = Column(String(100), nullable=True)   # e.g. "sensor.tv_remote_battery"
 
     batteries = relationship("Battery", back_populates="device")
+    logbook_entries = relationship(
+        "Logbook", secondary=device_logbook_table,
+        order_by="Logbook.recorded_at.desc()",
+        cascade="all, delete-orphan",
+        single_parent=True,
+    )
 
     def installed_count(self):
         return sum(1 for b in self.batteries if b.status == "installed")
@@ -69,6 +91,12 @@ class Battery(Base):
         order_by="BatteryPctLog.recorded_at.desc()",
         cascade="all, delete-orphan",
     )
+    logbook_entries = relationship(
+        "Logbook", secondary=battery_logbook_table,
+        order_by="Logbook.recorded_at.desc()",
+        cascade="all, delete-orphan",
+        single_parent=True,
+    )
 
     def is_available(self):
         return self.status == "available"
@@ -126,3 +154,18 @@ class BatteryPctLog(Base):
 
     def __repr__(self):
         return f"<BatteryPctLog {self.battery_id} {self.recorded_at} {self.percentage}%>"
+
+
+class Logbook(Base):
+    __tablename__ = "logbook"
+
+    id          = Column(Integer, primary_key=True, autoincrement=True)
+    body        = Column(Text, nullable=False)
+    recorded_at = Column(String(19), nullable=False)  # "YYYY-MM-DD HH:MM:SS"
+    # Note: SQLite has no native DATETIME type (stores dates as text).
+    # On MariaDB this would be a native DATETIME column — swap String(19) for
+    # DateTime when migrating, since SQLAlchemy's DateTime maps to DATETIME there.
+    # String(19) is used here to match every other timestamp column in the codebase.
+
+    def __repr__(self):
+        return f"<Logbook {self.recorded_at}>"

templates/base.html

@@ -334,6 +334,20 @@
 
     {% block content %}{% endblock %}
   </div>
+
+  <footer style="text-align:center;padding:1.25rem 1rem 1.5rem;margin-top:1rem;
+                  border-top:1px solid var(--border);font-size:0.8rem;">
+    <a href="{{ url_for('export_page') }}"
+       style="color:var(--text-muted);text-decoration:none;"
+       onmouseover="this.style.textDecoration='underline'"
+       onmouseout="this.style.textDecoration='none'">Export data</a>
+    <span style="color:var(--text-muted);margin:0 0.5rem;">·</span>
+    <a href="{{ url_for('import_page') }}"
+       style="color:var(--text-muted);text-decoration:none;"
+       onmouseover="this.style.textDecoration='underline'"
+       onmouseout="this.style.textDecoration='none'">Import data</a>
+  </footer>
+
   <div id="confirm-modal" role="dialog" aria-modal="true">
     <div id="confirm-modal-box">
       <p id="confirm-modal-msg"></p>

templates/battery_detail.html

@@ -216,6 +216,38 @@
   {% endif %}
 </div>
 
+<!-- Logbook -->
+<div class="card">
+  <h2>Logbook</h2>
+  {% if logbook_entries %}
+    <div style="display:flex;flex-direction:column;gap:0.6rem;margin-bottom:1rem;">
+      {% for entry in logbook_entries %}
+      <div style="border-left:3px solid var(--border);padding:0.35rem 0.75rem;
+                  display:flex;justify-content:space-between;align-items:flex-start;gap:0.5rem;">
+        <div>
+          <div class="text-muted" style="font-size:0.78rem;margin-bottom:0.15rem;">{{ entry.recorded_at }}</div>
+          <div style="white-space:pre-wrap;">{{ entry.body }}</div>
+        </div>
+        <form method="post"
+              action="{{ url_for('battery_logbook_delete', battery_id=battery.id, entry_id=entry.id) }}"
+              data-confirm="Delete this logbook entry?" data-confirm-ok="Delete">
+          <button class="btn btn-sm btn-danger" type="submit">Delete</button>
+        </form>
+      </div>
+      {% endfor %}
+    </div>
+  {% else %}
+    <p class="text-muted" style="margin-bottom:0.75rem;">No logbook entries yet.</p>
+  {% endif %}
+  <h3 style="font-size:1rem;margin:0.75rem 0 0.5rem;color:var(--text-h2);">Add Entry</h3>
+  <form method="post" action="{{ url_for('battery_logbook_add', battery_id=battery.id) }}">
+    <div class="form-group" style="margin-bottom:0.5rem;">
+      <textarea name="body" placeholder="Write a note…" rows="2" required style="min-height:60px;"></textarea>
+    </div>
+    <button class="btn btn-primary" type="submit">Add Entry</button>
+  </form>
+</div>
+
 <!-- Edit Details -->
 <div class="card">
   <h2>Edit Details</h2>

templates/device_add.html

@@ -18,6 +18,27 @@
              value="{{ form_slots|default(1) }}" min="1" required>
     </div>
 
+    <div class="form-group">
+      <label for="battery-size-select">Battery Size <span class="text-danger">*</span></label>
+      {% set _preset_sizes = ['AA','AAA','C','D','9V','CR2032','CR2025','CR2016','18650','14500','16340','26650','LR44/AG13'] %}
+      {% set _cur_size = form_battery_size|default('') %}
+      <select id="battery-size-select" onchange="metaSelectChanged(this,'battery_size')">
+        <option value="">— select —</option>
+        {% for s in _preset_sizes %}
+        <option value="{{ s }}" {% if _cur_size == s %}selected{% endif %}>{{ s }}</option>
+        {% endfor %}
+        {% for s in device_battery_sizes|default([]) %}
+          {% if s not in _preset_sizes %}
+        <option value="{{ s }}" {% if _cur_size == s %}selected{% endif %}>{{ s }}</option>
+          {% endif %}
+        {% endfor %}
+        <option value="__new__" {% if _cur_size and _cur_size not in _preset_sizes %}selected{% endif %}>Other…</option>
+      </select>
+      <input type="text" id="battery_size" name="battery_size" value="{{ _cur_size }}"
+             placeholder="e.g. CR123A"
+             style="display:{% if _cur_size and _cur_size not in _preset_sizes %}''{% else %}none{% endif %};margin-top:0.4rem;">
+    </div>
+
     <div class="form-group">
       <label>Type</label>
       {% set _preset_types = ['Remote Control','Game Controller','Flashlight','Lock','Sensor','Toy','Clock','Smoke Detector'] %}

templates/device_detail.html

@@ -39,6 +39,12 @@
       <td style="border:none;">{{ device.device_type }}</td>
     </tr>
     {% endif %}
+    {% if device.battery_size %}
+    <tr>
+      <td style="padding:0.3rem 1rem 0.3rem 0;font-weight:600;color:#64748b;border:none;">Battery Size</td>
+      <td style="border:none;">{{ device.battery_size }}</td>
+    </tr>
+    {% endif %}
     {% if device.has_mixed_brands() %}
     <tr>
       <td style="padding:0.3rem 1rem 0.3rem 0;font-weight:600;color:#64748b;border:none;">Warning</td>
@@ -79,7 +85,7 @@
 <div class="card">
   <h2>Install Batteries</h2>
   {% set free_slots = device.battery_slots - device.installed_count() %}
-  <p class="text-muted" style="margin-bottom:0.75rem;">{{ free_slots }} slot(s) free</p>
+  <p class="text-muted" style="margin-bottom:0.75rem;">{{ free_slots }} slot(s) free{% if device.battery_size %} &mdash; showing {{ device.battery_size }} batteries only{% endif %}</p>
   <form method="post" action="{{ url_for('device_install', device_id=device.id) }}">
     <div id="install-grid" style="display:grid;grid-template-columns:1fr auto;gap:0.4rem;max-width:400px;align-items:start;margin-bottom:0.5rem;">
       <span style="font-weight:600;font-size:0.85rem;color:#64748b;">Brand</span>
@@ -115,6 +121,14 @@ function editTypeSelectChanged(sel) {
     input.style.display = 'none'; input.value = sel.value;
   }
 }
+function editSizeSelectChanged(sel) {
+  var input = document.getElementById('edit-battery-size');
+  if (sel.value === '__new__') {
+    input.style.display = ''; input.value = ''; input.focus();
+  } else {
+    input.style.display = 'none'; input.value = sel.value;
+  }
+}
 function editLocationSelectChanged(sel) {
   var input = document.getElementById('edit-location');
   if (sel.value === '__new__') {
@@ -186,7 +200,7 @@ function addInstallRow() {
 </div>
 
 <div class="card">
-  <h2>Install Specific Battery</h2>
+  <h2>Install Specific Battery{% if device.battery_size %} <small class="text-muted" style="font-weight:normal;font-size:0.8rem;">({{ device.battery_size }} only)</small>{% endif %}</h2>
   {% if available_batteries %}
   <form method="post" action="{{ url_for('device_install_one', device_id=device.id) }}">
     <div class="form-group">
@@ -207,6 +221,37 @@ function addInstallRow() {
   {% endif %}
 </div>
 
+<div class="card">
+  <h2>Logbook</h2>
+  {% if logbook_entries %}
+    <div style="display:flex;flex-direction:column;gap:0.6rem;margin-bottom:1rem;">
+      {% for entry in logbook_entries %}
+      <div style="border-left:3px solid var(--border);padding:0.35rem 0.75rem;
+                  display:flex;justify-content:space-between;align-items:flex-start;gap:0.5rem;">
+        <div>
+          <div class="text-muted" style="font-size:0.78rem;margin-bottom:0.15rem;">{{ entry.recorded_at }}</div>
+          <div style="white-space:pre-wrap;">{{ entry.body }}</div>
+        </div>
+        <form method="post"
+              action="{{ url_for('device_logbook_delete', device_id=device.id, entry_id=entry.id) }}"
+              data-confirm="Delete this logbook entry?" data-confirm-ok="Delete">
+          <button class="btn btn-sm btn-danger" type="submit">Delete</button>
+        </form>
+      </div>
+      {% endfor %}
+    </div>
+  {% else %}
+    <p class="text-muted" style="margin-bottom:0.75rem;">No logbook entries yet.</p>
+  {% endif %}
+  <h3 style="font-size:1rem;margin:0.75rem 0 0.5rem;color:var(--text-h2);">Add Entry</h3>
+  <form method="post" action="{{ url_for('device_logbook_add', device_id=device.id) }}">
+    <div class="form-group" style="margin-bottom:0.5rem;">
+      <textarea name="body" placeholder="Write a note…" rows="2" required style="min-height:60px;"></textarea>
+    </div>
+    <button class="btn btn-primary" type="submit">Add Entry</button>
+  </form>
+</div>
+
 <div class="card">
   <h2>Edit Device</h2>
   <form method="post" action="{{ url_for('device_edit', device_id=device.id) }}">
@@ -238,6 +283,29 @@ function addInstallRow() {
              placeholder="Enter device type"
              style="display:{% if device.device_type and device.device_type not in _preset_types %}''{% else %}none{% endif %};margin-top:0.4rem;">
     </div>
+    <div class="form-group">
+      <label>Battery Size</label>
+      {% set _preset_sizes = ['AA','AAA','C','D','9V','CR2032','CR2025','CR2016','18650','14500','16340','26650','LR44/AG13'] %}
+      <select id="edit-battery-size-select" onchange="editSizeSelectChanged(this)">
+        <option value="">— none —</option>
+        {% for s in _preset_sizes %}
+        <option value="{{ s }}" {% if device.battery_size == s %}selected{% endif %}>{{ s }}</option>
+        {% endfor %}
+        {% for s in device_battery_sizes|default([]) %}
+          {% if s not in _preset_sizes %}
+        <option value="{{ s }}" {% if device.battery_size == s %}selected{% endif %}>{{ s }}</option>
+          {% endif %}
+        {% endfor %}
+        {% if device.battery_size and device.battery_size not in _preset_sizes and device.battery_size not in device_battery_sizes|default([]) %}
+        <option value="{{ device.battery_size }}" selected>{{ device.battery_size }}</option>
+        {% endif %}
+        <option value="__new__">Other…</option>
+      </select>
+      <input type="text" id="edit-battery-size" name="battery_size"
+             value="{{ device.battery_size or '' }}"
+             placeholder="e.g. CR123A"
+             style="display:{% if device.battery_size and device.battery_size not in _preset_sizes %}''{% else %}none{% endif %};margin-top:0.4rem;">
+    </div>
     <div class="form-group">
       <label>Location</label>
       <select id="edit-location-select" onchange="editLocationSelectChanged(this)">

templates/device_list.html

@@ -20,6 +20,13 @@
       <option value="{{ loc }}">{{ loc }}</option>
       {% endfor %}
     </select>
+    <select id="filter-battery-size" onchange="applyDeviceFilters()"
+            style="padding:0.25rem 0.5rem;font-size:0.85rem;border:1px solid #cbd5e1;border-radius:4px;">
+      <option value="">Any Size</option>
+      {% for sz in device_battery_sizes|default([]) %}
+      <option value="{{ sz }}">{{ sz }}</option>
+      {% endfor %}
+    </select>
     <select id="filter-fill" onchange="applyDeviceFilters()"
             style="padding:0.25rem 0.5rem;font-size:0.85rem;border:1px solid #cbd5e1;border-radius:4px;">
       <option value="">Any Fill</option>
@@ -40,6 +47,7 @@
         <tr>
           <th>Name</th>
           <th>Type</th>
+          <th>Size</th>
           <th>Location</th>
           <th>Slots</th>
           <th>Installed</th>
@@ -54,11 +62,13 @@
         {% elif installed >= d.battery_slots %}{% set fill_state = 'full' %}
         {% else %}{% set fill_state = 'partial' %}{% endif %}
         <tr data-type="{{ d.device_type or '' }}"
+            data-battery-size="{{ d.battery_size or '' }}"
             data-location="{{ d.location or '' }}"
             data-fill="{{ fill_state }}"
             data-name="{{ d.name|lower }}">
           <td data-label="Device"><a href="{{ url_for('device_detail', device_id=d.id) }}"><strong>{{ d.name }}</strong></a></td>
           <td data-label="Type">{{ d.device_type or '—' }}</td>
+          <td data-label="Size">{{ d.battery_size or '—' }}</td>
           <td data-label="Location">{{ d.location or '—' }}</td>
           <td data-label="Slots">{{ d.battery_slots }}</td>
           <td data-label="Installed">
@@ -95,7 +105,7 @@
           </td>
         </tr>
         {% else %}
-        <tr><td colspan="7" class="text-muted" style="text-align:center;padding:1rem;">No devices yet. <a href="{{ url_for('device_add') }}">Add one.</a></td></tr>
+        <tr><td colspan="8" class="text-muted" style="text-align:center;padding:1rem;">No devices yet. <a href="{{ url_for('device_add') }}">Add one.</a></td></tr>
         {% endfor %}
       </tbody>
     </table>
@@ -106,27 +116,31 @@
 
 <script>
 function applyDeviceFilters() {
-  var typeVal     = document.getElementById('filter-type').value;
+  var typeVal        = document.getElementById('filter-type').value;
-  var locationVal = document.getElementById('filter-location').value;
+  var batterySizeVal = document.getElementById('filter-battery-size').value;
-  var fillVal     = document.getElementById('filter-fill').value;
+  var locationVal    = document.getElementById('filter-location').value;
-  var textVal     = document.getElementById('filter-device-text').value.toLowerCase();
+  var fillVal        = document.getElementById('filter-fill').value;
-  var rows        = document.querySelectorAll('tbody tr[data-name]');
+  var textVal        = document.getElementById('filter-device-text').value.toLowerCase();
-  var visible     = 0;
+  var rows           = document.querySelectorAll('tbody tr[data-name]');
+  var visible        = 0;
   rows.forEach(function(row) {
-    var rowType     = row.dataset.type     || '';
+    var rowType        = row.dataset.type        || '';
-    var rowLocation = row.dataset.location || '';
+    var rowBatterySize = row.dataset.batterySize || '';
-    var rowFill     = row.dataset.fill     || '';
+    var rowLocation    = row.dataset.location    || '';
-    var rowName     = row.dataset.name     || '';
+    var rowFill        = row.dataset.fill        || '';
-    var show = (!typeVal     || rowType === typeVal) &&
+    var rowName        = row.dataset.name        || '';
-               (!locationVal || rowLocation === locationVal) &&
+    var show = (!typeVal        || rowType === typeVal) &&
-               (!fillVal     || rowFill === fillVal) &&
+               (!batterySizeVal || rowBatterySize === batterySizeVal) &&
-               (!textVal     || rowName.includes(textVal) ||
+               (!locationVal    || rowLocation === locationVal) &&
-                                rowType.toLowerCase().includes(textVal) ||
+               (!fillVal        || rowFill === fillVal) &&
-                                rowLocation.toLowerCase().includes(textVal));
+               (!textVal        || rowName.includes(textVal) ||
+                                   rowType.toLowerCase().includes(textVal) ||
+                                   rowBatterySize.toLowerCase().includes(textVal) ||
+                                   rowLocation.toLowerCase().includes(textVal));
     row.style.display = show ? '' : 'none';
     if (show) visible++;
   });
-  var active = typeVal || locationVal || fillVal || textVal;
+  var active = typeVal || batterySizeVal || locationVal || fillVal || textVal;
   document.getElementById('device-filter-reset').style.display = active ? '' : 'none';
   document.getElementById('device-filter-count').textContent =
     active ? (visible + ' of ' + rows.length + ' shown') : '';
@@ -134,6 +148,7 @@ function applyDeviceFilters() {
 
 function resetDeviceFilters() {
   document.getElementById('filter-type').value = '';
+  document.getElementById('filter-battery-size').value = '';
   document.getElementById('filter-location').value = '';
   document.getElementById('filter-fill').value = '';
   document.getElementById('filter-device-text').value = '';

templates/export.html

@@ -0,0 +1,70 @@
+{% extends "base.html" %}
+{% block title %}Export — Battery Tracker{% endblock %}
+
+{% block content %}
+<h1 style="margin-bottom:1.25rem;">Export Data</h1>
+
+<div class="card" style="margin-bottom:1rem;">
+  <h2 style="margin-bottom:0.5rem;">Full Export</h2>
+  <p style="color:var(--text-muted,#6b7280);margin-bottom:1rem;">
+    Download your complete dataset — batteries, devices, charge logs, capacity tests, and percentage history.
+  </p>
+  <div style="display:flex;gap:0.75rem;flex-wrap:wrap;">
+    <a href="{{ url_for('export_csv_zip') }}" class="btn btn-primary">Download All CSVs (.zip)</a>
+    <a href="{{ url_for('export_json') }}" class="btn btn-secondary">Download JSON</a>
+  </div>
+</div>
+
+<div class="card">
+  <h2 style="margin-bottom:0.5rem;">Individual CSV Files</h2>
+  <p style="color:var(--text-muted,#6b7280);margin-bottom:1rem;">Download a single table at a time.</p>
+  <table style="border-collapse:collapse;width:100%;">
+    <tbody>
+      <tr>
+        <td style="padding:0.4rem 0.75rem 0.4rem 0;">
+          <a href="{{ url_for('export_batteries_csv') }}" class="btn btn-sm btn-secondary">batteries.csv</a>
+        </td>
+        <td style="padding:0.4rem 0;color:var(--text-muted,#6b7280);font-size:0.9rem;">
+          All batteries with device name
+        </td>
+      </tr>
+      <tr>
+        <td style="padding:0.4rem 0.75rem 0.4rem 0;">
+          <a href="{{ url_for('export_devices_csv') }}" class="btn btn-sm btn-secondary">devices.csv</a>
+        </td>
+        <td style="padding:0.4rem 0;color:var(--text-muted,#6b7280);font-size:0.9rem;">
+          All devices with installed battery count
+        </td>
+      </tr>
+      <tr>
+        <td style="padding:0.4rem 0.75rem 0.4rem 0;">
+          <a href="{{ url_for('export_charge_logs_csv') }}" class="btn btn-sm btn-secondary">charge-logs.csv</a>
+        </td>
+        <td style="padding:0.4rem 0;color:var(--text-muted,#6b7280);font-size:0.9rem;">
+          All charge log entries with battery label
+        </td>
+      </tr>
+      <tr>
+        <td style="padding:0.4rem 0.75rem 0.4rem 0;">
+          <a href="{{ url_for('export_capacity_tests_csv') }}" class="btn btn-sm btn-secondary">capacity-tests.csv</a>
+        </td>
+        <td style="padding:0.4rem 0;color:var(--text-muted,#6b7280);font-size:0.9rem;">
+          All capacity test results with battery label
+        </td>
+      </tr>
+      <tr>
+        <td style="padding:0.4rem 0.75rem 0.4rem 0;">
+          <a href="{{ url_for('export_pct_logs_csv') }}" class="btn btn-sm btn-secondary">pct-logs.csv</a>
+        </td>
+        <td style="padding:0.4rem 0;color:var(--text-muted,#6b7280);font-size:0.9rem;">
+          Battery percentage history
+        </td>
+      </tr>
+    </tbody>
+  </table>
+</div>
+
+<div style="margin-top:0.75rem;">
+  <a href="{{ url_for('import_page') }}" class="btn btn-secondary">Import JSON</a>
+</div>
+{% endblock %}

templates/import.html

@@ -0,0 +1,73 @@
+{% extends "base.html" %}
+{% block title %}Import — Battery Tracker{% endblock %}
+
+{% block content %}
+<h1 style="margin-bottom:1.25rem;">Import Data</h1>
+
+<div class="card" style="margin-bottom:1rem;">
+  <p style="color:var(--text-muted,#6b7280);margin-bottom:1rem;">
+    Upload a JSON file exported from Battery Tracker.
+    Devices are matched by name and batteries by label — existing records are skipped (not overwritten).
+    Charge logs, capacity tests, and percentage logs are always appended.
+  </p>
+  <form method="POST" action="{{ url_for('import_page') }}" enctype="multipart/form-data">
+    <div class="form-group">
+      <label for="file">JSON Export File</label>
+      <input type="file" id="file" name="file" accept=".json,application/json" required
+             style="width:100%;padding:0.45rem 0.65rem;border:1px solid var(--border-input,#d1d5db);
+                    border-radius:4px;font-size:0.9rem;background:var(--bg-input,#fff);
+                    color:var(--text-body,#111827);">
+    </div>
+    <div class="form-actions">
+      <button type="submit" class="btn btn-primary">Import</button>
+      <a href="{{ url_for('export_page') }}" class="btn btn-secondary">Back to Export</a>
+    </div>
+  </form>
+</div>
+
+{% if results is not none %}
+<div class="card">
+  <h2 style="margin-bottom:1rem;">Import Results</h2>
+  <table style="border-collapse:collapse;width:100%;max-width:480px;">
+    <thead>
+      <tr style="border-bottom:2px solid var(--border,#e5e7eb);">
+        <th style="text-align:left;padding:0.4rem 0.75rem 0.4rem 0;font-size:0.85rem;color:var(--text-muted,#6b7280);font-weight:600;">Category</th>
+        <th style="text-align:right;padding:0.4rem 0.75rem;font-size:0.85rem;color:var(--text-muted,#6b7280);font-weight:600;">Created / Appended</th>
+        <th style="text-align:right;padding:0.4rem 0;font-size:0.85rem;color:var(--text-muted,#6b7280);font-weight:600;">Skipped</th>
+      </tr>
+    </thead>
+    <tbody>
+      <tr style="border-bottom:1px solid var(--border,#e5e7eb);">
+        <td style="padding:0.45rem 0.75rem 0.45rem 0;">Devices</td>
+        <td style="text-align:right;padding:0.45rem 0.75rem;">{{ results.devices_created }}</td>
+        <td style="text-align:right;padding:0.45rem 0;">{{ results.devices_skipped }}</td>
+      </tr>
+      <tr style="border-bottom:1px solid var(--border,#e5e7eb);">
+        <td style="padding:0.45rem 0.75rem 0.45rem 0;">Batteries</td>
+        <td style="text-align:right;padding:0.45rem 0.75rem;">{{ results.batteries_created }}</td>
+        <td style="text-align:right;padding:0.45rem 0;">{{ results.batteries_skipped }}</td>
+      </tr>
+      <tr style="border-bottom:1px solid var(--border,#e5e7eb);">
+        <td style="padding:0.45rem 0.75rem 0.45rem 0;">Charge Logs</td>
+        <td style="text-align:right;padding:0.45rem 0.75rem;">{{ results.charge_logs_appended }}</td>
+        <td style="text-align:right;padding:0.45rem 0;">{{ results.charge_logs_skipped }}</td>
+      </tr>
+      <tr style="border-bottom:1px solid var(--border,#e5e7eb);">
+        <td style="padding:0.45rem 0.75rem 0.45rem 0;">Capacity Tests</td>
+        <td style="text-align:right;padding:0.45rem 0.75rem;">{{ results.capacity_tests_appended }}</td>
+        <td style="text-align:right;padding:0.45rem 0;">{{ results.capacity_tests_skipped }}</td>
+      </tr>
+      <tr>
+        <td style="padding:0.45rem 0.75rem 0.45rem 0;">% Logs</td>
+        <td style="text-align:right;padding:0.45rem 0.75rem;">{{ results.pct_logs_appended }}</td>
+        <td style="text-align:right;padding:0.45rem 0;">{{ results.pct_logs_skipped }}</td>
+      </tr>
+    </tbody>
+  </table>
+  <div style="margin-top:1.25rem;display:flex;gap:0.75rem;flex-wrap:wrap;">
+    <a href="{{ url_for('dashboard') }}" class="btn btn-primary">Go to Dashboard</a>
+    <a href="{{ url_for('import_page') }}" class="btn btn-secondary">Import Another File</a>
+  </div>
+</div>
+{% endif %}
+{% endblock %}

tests/conftest.py

@@ -42,8 +42,8 @@ def seeded_client(app):
       id=3  BrandX 002  (BrandX, retired)
     """
     with app.test_client() as c:
-        c.post("/device/add", data={"name": "Device A", "battery_slots": "2"})
+        c.post("/device/add", data={"name": "Device A", "battery_slots": "2", "battery_size": "AA"})
-        c.post("/device/add", data={"name": "Device B", "battery_slots": "1"})
+        c.post("/device/add", data={"name": "Device B", "battery_slots": "1", "battery_size": "AA"})
         c.post("/battery/add", data={"brand": "BrandX", "count": "1"})  # id=1
         c.post("/battery/add", data={"brand": "BrandY", "count": "1"})  # id=2
         c.post("/battery/add", data={"brand": "BrandX", "count": "1"})  # id=3

tests/test_acceptance.py

@@ -235,7 +235,7 @@ def test_bulk_delete(client):
 
 
 def test_bulk_unassign(client):
-    client.post("/device/add", data={"name": "Gadget", "battery_slots": "2"})
+    client.post("/device/add", data={"name": "Gadget", "battery_slots": "2", "battery_size": "AA"})
     client.post("/battery/add", data={"brand": "TestBrand", "count": "2"})
     client.post("/device/1/install", data={"brand[]": "TestBrand", "qty[]": "2"})
     resp = client.post("/battery/bulk-action",
@@ -269,7 +269,7 @@ def test_bulk_action_no_selection(client):
 # ------------------------------------------------------------------ #
 
 def test_device_install_autoselects(client):
-    client.post("/device/add", data={"name": "Gadget", "battery_slots": "2"})
+    client.post("/device/add", data={"name": "Gadget", "battery_slots": "2", "battery_size": "AA"})
     client.post("/battery/add", data={"brand": "Eneloop", "count": "3"})
     resp = client.post("/device/1/install",
                        data={"brand[]": "Eneloop", "qty[]": "2"},
@@ -281,7 +281,7 @@ def test_device_install_autoselects(client):
 
 
 def test_device_install_mixed_brands(client):
-    client.post("/device/add", data={"name": "Remote", "battery_slots": "4"})
+    client.post("/device/add", data={"name": "Remote", "battery_slots": "4", "battery_size": "AA"})
     client.post("/battery/add", data={"brand": "Eneloop", "count": "2"})
     client.post("/battery/add", data={"brand": "Energizer", "count": "2"})
     resp = client.post("/device/1/install",
@@ -293,7 +293,7 @@ def test_device_install_mixed_brands(client):
 
 
 def test_device_install_insufficient_batteries(client):
-    client.post("/device/add", data={"name": "Gadget", "battery_slots": "4"})
+    client.post("/device/add", data={"name": "Gadget", "battery_slots": "4", "battery_size": "AA"})
     client.post("/battery/add", data={"brand": "Eneloop", "count": "1"})
     resp = client.post("/device/1/install",
                        data={"brand[]": "Eneloop", "qty[]": "2"},
@@ -303,7 +303,7 @@ def test_device_install_insufficient_batteries(client):
 
 
 def test_device_install_over_capacity(client):
-    client.post("/device/add", data={"name": "Gadget", "battery_slots": "1"})
+    client.post("/device/add", data={"name": "Gadget", "battery_slots": "1", "battery_size": "AA"})
     client.post("/battery/add", data={"brand": "Eneloop", "count": "3"})
     resp = client.post("/device/1/install",
                        data={"brand[]": "Eneloop", "qty[]": "3"},
@@ -314,7 +314,7 @@ def test_device_install_over_capacity(client):
 
 def test_bulk_install_device(client):
     """Select multiple available batteries and install them into a device."""
-    client.post("/device/add", data={"name": "Box", "battery_slots": "3"})
+    client.post("/device/add", data={"name": "Box", "battery_slots": "3", "battery_size": "AA"})
     client.post("/battery/add", data={"brand": "Eneloop", "count": "2"})
     resp = client.post("/battery/bulk-action",
                        data={"battery_ids": ["1", "2"], "action": "install_device",
@@ -326,7 +326,7 @@ def test_bulk_install_device(client):
 
 def test_bulk_install_device_over_capacity(client):
     """Bulk install is blocked when device lacks free slots."""
-    client.post("/device/add", data={"name": "Box", "battery_slots": "1"})
+    client.post("/device/add", data={"name": "Box", "battery_slots": "1", "battery_size": "AA"})
     client.post("/battery/add", data={"brand": "Eneloop", "count": "2"})
     resp = client.post("/battery/bulk-action",
                        data={"battery_ids": ["1", "2"], "action": "install_device",
@@ -338,8 +338,8 @@ def test_bulk_install_device_over_capacity(client):
 
 def test_bulk_install_device_moves_installed_battery(client):
     """Bulk install moves a battery already installed in another device."""
-    client.post("/device/add", data={"name": "Box A", "battery_slots": "2"})
+    client.post("/device/add", data={"name": "Box A", "battery_slots": "2", "battery_size": "AA"})
-    client.post("/device/add", data={"name": "Box B", "battery_slots": "2"})
+    client.post("/device/add", data={"name": "Box B", "battery_slots": "2", "battery_size": "AA"})
     client.post("/battery/add", data={"brand": "Eneloop", "count": "1"})
     client.post("/battery/1/assign", data={"device_id": "1"})
     resp = client.post("/battery/bulk-action",
@@ -357,7 +357,7 @@ def test_bulk_install_device_moves_installed_battery(client):
 
 def test_dashboard_quick_assign(client):
     """Quick-assign from dashboard (battery_assign POST) succeeds."""
-    client.post("/device/add", data={"name": "Box", "battery_slots": "2"})
+    client.post("/device/add", data={"name": "Box", "battery_slots": "2", "battery_size": "AA"})
     client.post("/battery/add", data={"brand": "Eneloop", "count": "1"})
     resp = client.post("/battery/1/assign", data={"device_id": "1"},
                        follow_redirects=True)
@@ -367,7 +367,7 @@ def test_dashboard_quick_assign(client):
 
 def test_dashboard_quick_assign_full_device_blocked(client):
     """Quick-assign from dashboard to a full device is blocked."""
-    client.post("/device/add", data={"name": "Box", "battery_slots": "1"})
+    client.post("/device/add", data={"name": "Box", "battery_slots": "1", "battery_size": "AA"})
     client.post("/battery/add", data={"brand": "Eneloop", "count": "2"})
     client.post("/battery/1/assign", data={"device_id": "1"})  # fills the slot
     resp = client.post("/battery/2/assign", data={"device_id": "1"},
@@ -382,7 +382,7 @@ def test_dashboard_quick_assign_full_device_blocked(client):
 
 def test_install_one_specific_battery(client):
     """device_install_one installs a chosen battery."""
-    client.post("/device/add", data={"name": "Box", "battery_slots": "2"})
+    client.post("/device/add", data={"name": "Box", "battery_slots": "2", "battery_size": "AA"})
     client.post("/battery/add", data={"brand": "Eneloop", "count": "1"})
     resp = client.post("/device/1/install-one", data={"battery_id": "1"},
                        follow_redirects=True)
@@ -392,7 +392,7 @@ def test_install_one_specific_battery(client):
 
 def test_install_one_over_capacity_blocked(client):
     """device_install_one to a full device is blocked."""
-    client.post("/device/add", data={"name": "Box", "battery_slots": "1"})
+    client.post("/device/add", data={"name": "Box", "battery_slots": "1", "battery_size": "AA"})
     client.post("/battery/add", data={"brand": "Eneloop", "count": "2"})
     client.post("/device/1/install-one", data={"battery_id": "1"})  # fills slot
     resp = client.post("/device/1/install-one", data={"battery_id": "2"},
@@ -418,7 +418,7 @@ def test_device_list(seeded_client):
 
 def test_add_device(client):
     resp = client.post("/device/add",
-                       data={"name": "My Gadget", "battery_slots": "3"},
+                       data={"name": "My Gadget", "battery_slots": "3", "battery_size": "AA"},
                        follow_redirects=True)
     assert resp.status_code == 200
     assert b"My Gadget" in resp.data
@@ -426,7 +426,7 @@ def test_add_device(client):
 
 def test_add_device_duplicate_name(seeded_client):
     resp = seeded_client.post("/device/add",
-                              data={"name": "Device A", "battery_slots": "2"})
+                              data={"name": "Device A", "battery_slots": "2", "battery_size": "AA"})
     assert resp.status_code == 400
     assert b"already exists" in resp.data
 
@@ -476,21 +476,22 @@ def test_delete_device_removed(seeded_client):
 
 def test_add_device_with_type(client):
     resp = client.post("/device/add",
-                       data={"name": "TV Remote", "battery_slots": "2", "device_type": "Remote Control"},
+                       data={"name": "TV Remote", "battery_slots": "2", "battery_size": "AA",
+                             "device_type": "Remote Control"},
                        follow_redirects=True)
     assert resp.status_code == 200
     assert b"TV Remote" in resp.data
 
 
 def test_device_detail_shows_type(client):
-    client.post("/device/add", data={"name": "Torch", "battery_slots": "1", "device_type": "Flashlight"})
+    client.post("/device/add", data={"name": "Torch", "battery_slots": "1", "battery_size": "AA", "device_type": "Flashlight"})
     resp = client.get("/device/1")
     assert resp.status_code == 200
     assert b"Flashlight" in resp.data
 
 
 def test_edit_device_type(client):
-    client.post("/device/add", data={"name": "Torch", "battery_slots": "1"})
+    client.post("/device/add", data={"name": "Torch", "battery_slots": "1", "battery_size": "AA"})
     resp = client.post("/device/1/edit",
                        data={"name": "Torch", "battery_slots": "1", "device_type": "Flashlight"},
                        follow_redirects=True)
@@ -500,7 +501,8 @@ def test_edit_device_type(client):
 
 def test_add_device_with_location(client):
     resp = client.post("/device/add",
-                       data={"name": "Bedroom Remote", "battery_slots": "2", "location": "Bedroom"},
+                       data={"name": "Bedroom Remote", "battery_slots": "2", "battery_size": "AA",
+                             "location": "Bedroom"},
                        follow_redirects=True)
     assert resp.status_code == 200
     assert b"Bedroom Remote" in resp.data
@@ -509,7 +511,7 @@ def test_add_device_with_location(client):
 
 
 def test_edit_device_location(client):
-    client.post("/device/add", data={"name": "Living Room Clock", "battery_slots": "1"})
+    client.post("/device/add", data={"name": "Living Room Clock", "battery_slots": "1", "battery_size": "AA"})
     resp = client.post("/device/1/edit",
                        data={"name": "Living Room Clock", "battery_slots": "1", "location": "Living Room"},
                        follow_redirects=True)
@@ -545,7 +547,7 @@ def test_delete_capacity_test(client):
 
 
 def test_add_install_delete_battery(client):
-    client.post("/device/add", data={"name": "Gadget", "battery_slots": "1"})
+    client.post("/device/add", data={"name": "Gadget", "battery_slots": "1", "battery_size": "AA"})
     client.post("/battery/add", data={"brand": "AcmeBrand", "count": "1"})
     resp = client.post("/device/1/install",
                        data={"brand[]": "AcmeBrand", "qty[]": "1"},
@@ -553,3 +555,255 @@ def test_add_install_delete_battery(client):
     assert b"Gadget" in resp.data
     client.post("/battery/1/delete")
     assert client.get("/battery/1").status_code == 404
+
+
+# ------------------------------------------------------------------ #
+# Device — battery_size
+# ------------------------------------------------------------------ #
+
+def test_add_device_requires_battery_size(client):
+    """POST without battery_size returns 400."""
+    resp = client.post("/device/add", data={"name": "No Size Device", "battery_slots": "2"})
+    assert resp.status_code == 400
+    assert b"Battery size is required" in resp.data
+
+
+def test_add_device_with_battery_size(client):
+    """Device with battery_size shows it on detail page."""
+    resp = client.post("/device/add",
+                       data={"name": "AA Remote", "battery_slots": "2", "battery_size": "AA"},
+                       follow_redirects=True)
+    assert resp.status_code == 200
+    resp2 = client.get("/device/1")
+    assert b"AA" in resp2.data
+
+
+def test_install_one_filters_by_size(client):
+    """Single-battery install dropdown excludes batteries with wrong size."""
+    client.post("/device/add", data={"name": "AA Device", "battery_slots": "2", "battery_size": "AA"})
+    client.post("/battery/add", data={"brand": "Eneloop", "count": "1"})    # id=1
+    client.post("/battery/1/edit-details", data={"size": "AA"})
+    client.post("/battery/add", data={"brand": "Energizer", "count": "1"})  # id=2
+    client.post("/battery/2/edit-details", data={"size": "AAA"})
+    resp = client.get("/device/1")
+    assert resp.status_code == 200
+    # AA battery should appear in the dropdown, AAA should not
+    assert b"Eneloop 001" in resp.data
+    assert b"Energizer 001" not in resp.data
+
+
+def test_bulk_install_filters_by_size(client):
+    """Bulk install with a brand that only has wrong-size batteries fails with 0 available."""
+    client.post("/device/add", data={"name": "AA Device", "battery_slots": "2", "battery_size": "AA"})
+    client.post("/battery/add", data={"brand": "Energizer", "count": "2"})
+    # Set both batteries to AAA (explicitly incompatible)
+    client.post("/battery/1/edit-details", data={"size": "AAA"})
+    client.post("/battery/2/edit-details", data={"size": "AAA"})
+    resp = client.post("/device/1/install",
+                       data={"brand[]": "Energizer", "qty[]": "1"},
+                       follow_redirects=True)
+    assert resp.status_code == 200
+
+
+# ------------------------------------------------------------------ #
+# Import
+# ------------------------------------------------------------------ #
+
+import io
+import json as _json
+
+
+def _make_import_payload(devices=None, batteries=None,
+                         charge_logs=None, capacity_tests=None, pct_logs=None):
+    data = {
+        "exported_at": "2026-01-01T00:00:00",
+        "devices":        devices        or [],
+        "batteries":      batteries      or [],
+        "charge_logs":    charge_logs    or [],
+        "capacity_tests": capacity_tests or [],
+        "pct_logs":       pct_logs       or [],
+    }
+    return (io.BytesIO(_json.dumps(data).encode()), "export.json")
+
+
+def _post_import(client, payload_tuple):
+    buf, fname = payload_tuple
+    return client.post(
+        "/import",
+        data={"file": (buf, fname)},
+        content_type="multipart/form-data",
+    )
+
+
+def _bat(id, label, brand="Brand", status="available", device_id=None, **kw):
+    return {"id": id, "label": label, "brand": brand, "status": status,
+            "device_id": device_id, "size": None, "chemistry": None, "capacity_mah": None,
+            "tested_capacity_mah": None, "tested_date": None, "charge_cycles": None,
+            "purchase_date": None, "storage_location": None, "battery_percentage": None,
+            "notes": None, **kw}
+
+
+def _dev(id, name, battery_slots=2, battery_size="AA", **kw):
+    return {"id": id, "name": name, "battery_slots": battery_slots,
+            "battery_size": battery_size, "device_type": None,
+            "location": None, "ha_entity_id": None, "notes": None, **kw}
+
+
+def test_import_page_loads(client):
+    resp = client.get("/import")
+    assert resp.status_code == 200
+    assert b"Import" in resp.data
+    assert b'enctype="multipart/form-data"' in resp.data
+
+
+def test_import_no_file_returns_400(client):
+    resp = client.post("/import", data={}, content_type="multipart/form-data")
+    assert resp.status_code == 400
+
+
+def test_import_invalid_json_returns_400(client):
+    buf = io.BytesIO(b"this is not json")
+    resp = client.post("/import",
+                       data={"file": (buf, "bad.json")},
+                       content_type="multipart/form-data")
+    assert resp.status_code == 400
+    assert b"Invalid JSON" in resp.data
+
+
+def test_import_missing_required_keys_returns_400(client):
+    buf = io.BytesIO(_json.dumps({"exported_at": "2026-01-01"}).encode())
+    resp = client.post("/import",
+                       data={"file": (buf, "bad.json")},
+                       content_type="multipart/form-data")
+    assert resp.status_code == 400
+
+
+def test_import_creates_devices_and_batteries(client):
+    payload = _make_import_payload(
+        devices=[_dev(1, "RC Car")],
+        batteries=[_bat(1, "Eneloop 001", brand="Eneloop")],
+    )
+    resp = _post_import(client, payload)
+    assert resp.status_code == 200
+    assert b"Import Results" in resp.data
+    dash = client.get("/")
+    assert b"Eneloop 001" in dash.data
+    assert b"RC Car" in dash.data
+
+
+def test_import_results_show_correct_counts(client):
+    payload = _make_import_payload(
+        devices=[_dev(10, "DevX")],
+        batteries=[_bat(10, "BrandX 001"), _bat(11, "BrandX 002")],
+    )
+    resp = _post_import(client, payload)
+    assert resp.status_code == 200
+    # devices_created=1, batteries_created=2 appear in the results table
+    assert b"Import Results" in resp.data
+
+
+def test_import_charge_logs_remapped_correctly(client):
+    payload = _make_import_payload(
+        batteries=[_bat(99, "Eneloop 001", brand="Eneloop")],
+        charge_logs=[{"id": 1, "battery_id": 99, "battery_label": "Eneloop 001",
+                      "charged_date": "2026-01-15", "increment_cycles": 1, "notes": None}],
+    )
+    resp = _post_import(client, payload)
+    assert resp.status_code == 200
+    detail = client.get("/battery/1")
+    assert b"2026-01-15" in detail.data
+
+
+def test_import_capacity_tests_remapped(client):
+    payload = _make_import_payload(
+        batteries=[_bat(5, "Test 001", capacity_mah=2000)],
+        capacity_tests=[{"id": 1, "battery_id": 5, "battery_label": "Test 001",
+                         "tested_capacity_mah": 1850, "tested_date": "2026-02-01", "notes": None}],
+    )
+    resp = _post_import(client, payload)
+    assert resp.status_code == 200
+    detail = client.get("/battery/1")
+    assert b"1850" in detail.data
+
+
+def test_import_skips_existing_device(client):
+    client.post("/device/add", data={"name": "RC Car", "battery_slots": "2", "battery_size": "AA"})
+    payload = _make_import_payload(
+        devices=[_dev(1, "RC Car", battery_slots=4)],
+    )
+    resp = _post_import(client, payload)
+    assert resp.status_code == 200
+    # Original 2-slot device not overwritten
+    detail = client.get("/device/1")
+    assert b"RC Car" in detail.data
+
+
+def test_import_skips_existing_battery(client):
+    client.post("/battery/add", data={"brand": "Eneloop", "count": "1"})
+    payload = _make_import_payload(
+        batteries=[_bat(999, "Eneloop 001", brand="Eneloop", status="retired")],
+    )
+    resp = _post_import(client, payload)
+    assert resp.status_code == 200
+    detail = client.get("/battery/1")
+    assert b"available" in detail.data.lower()
+
+
+def test_import_log_skipped_when_battery_not_in_map(client):
+    payload = _make_import_payload(
+        batteries=[],
+        charge_logs=[{"id": 1, "battery_id": 42, "battery_label": "Ghost",
+                      "charged_date": "2026-01-01", "increment_cycles": 1, "notes": None}],
+    )
+    resp = _post_import(client, payload)
+    assert resp.status_code == 200
+    assert b"Import Results" in resp.data
+
+
+def test_import_battery_gets_installed_when_device_maps(client):
+    payload = _make_import_payload(
+        devices=[_dev(7, "My Device")],
+        batteries=[_bat(7, "Linked 001", status="installed", device_id=7)],
+    )
+    resp = _post_import(client, payload)
+    assert resp.status_code == 200
+    detail = client.get("/battery/1")
+    assert b"installed" in detail.data.lower()
+    assert b"My Device" in detail.data
+
+
+def test_import_battery_retired_preserved_when_no_device(client):
+    payload = _make_import_payload(
+        batteries=[_bat(3, "Old 001", status="retired")],
+    )
+    resp = _post_import(client, payload)
+    assert resp.status_code == 200
+    detail = client.get("/battery/1")
+    assert b"retired" in detail.data.lower()
+
+
+def test_import_battery_device_id_unknown_becomes_available(client):
+    payload = _make_import_payload(
+        devices=[],
+        batteries=[_bat(5, "Orphan 001", status="installed", device_id=99)],
+    )
+    resp = _post_import(client, payload)
+    assert resp.status_code == 200
+    detail = client.get("/battery/1")
+    assert b"available" in detail.data.lower()
+
+
+def test_full_roundtrip_export_import(client):
+    client.post("/device/add", data={"name": "Router", "battery_slots": "1", "battery_size": "AA"})
+    client.post("/battery/add", data={"brand": "Eneloop", "count": "1"})
+    client.post("/battery/1/assign", data={"device_id": "1"})
+
+    export_resp = client.get("/export/all.json")
+    assert export_resp.status_code == 200
+
+    buf = io.BytesIO(export_resp.data)
+    resp = client.post("/import",
+                       data={"file": (buf, "export.json")},
+                       content_type="multipart/form-data")
+    assert resp.status_code == 200
+    assert b"Import Results" in resp.data

tests/test_ha_integration.py

@@ -62,7 +62,7 @@ def test_ha_disabled_dashboard_no_ha_column(client):
 
 
 def test_ha_disabled_device_no_ha_field(client):
-    client.post("/device/add", data={"name": "Dev A", "battery_slots": "1"})
+    client.post("/device/add", data={"name": "Dev A", "battery_slots": "1", "battery_size": "AA"})
     resp = client.get("/device/1")
     assert resp.status_code == 200
     assert b"ha_entity_id" not in resp.data
@@ -153,13 +153,13 @@ def _make_session_factory(ha_app):
 
 def test_poll_updates_installed_batteries(ha_app, ha_client_f):
     """Installed battery in a device with ha_entity_id gets battery_percentage updated."""
-    ha_client_f.post("/device/add", data={"name": "Dev A", "battery_slots": "2"})
+    ha_client_f.post("/device/add", data={"name": "Dev A", "battery_slots": "2", "battery_size": "AA"})
     ha_client_f.post("/battery/add", data={"brand": "X", "count": "1"})
     # Assign battery to device
     ha_client_f.post("/battery/1/assign", data={"device_id": "1"})
     # Set ha_entity_id on device
     ha_client_f.post("/device/1/edit", data={
-        "name": "Dev A", "battery_slots": "2", "ha_entity_id": "sensor.dev_a_battery"
+        "name": "Dev A", "battery_slots": "2", "battery_size": "AA", "ha_entity_id": "sensor.dev_a_battery"
     })
 
     from ha_client import HomeAssistantClient
@@ -184,11 +184,11 @@ def test_poll_updates_installed_batteries(ha_app, ha_client_f):
 
 def test_poll_skips_uninstalled_batteries(ha_app, ha_client_f):
     """Batteries that are available (not installed) are not updated by the poller."""
-    ha_client_f.post("/device/add", data={"name": "Dev B", "battery_slots": "1"})
+    ha_client_f.post("/device/add", data={"name": "Dev B", "battery_slots": "1", "battery_size": "AA"})
     ha_client_f.post("/battery/add", data={"brand": "X", "count": "1"})
     # Set entity on device but do NOT install the battery
     ha_client_f.post("/device/1/edit", data={
-        "name": "Dev B", "battery_slots": "1", "ha_entity_id": "sensor.dev_b_battery"
+        "name": "Dev B", "battery_slots": "1", "battery_size": "AA", "ha_entity_id": "sensor.dev_b_battery"
     })
 
     from ha_client import HomeAssistantClient
@@ -211,7 +211,7 @@ def test_poll_skips_uninstalled_batteries(ha_app, ha_client_f):
 
 def test_poll_skips_devices_without_entity_id(ha_app, ha_client_f):
     """Devices with no ha_entity_id must never reach get_state."""
-    ha_client_f.post("/device/add", data={"name": "Dev C", "battery_slots": "1"})
+    ha_client_f.post("/device/add", data={"name": "Dev C", "battery_slots": "1", "battery_size": "AA"})
 
     from ha_client import HomeAssistantClient
     from ha_poller import HaPoller
@@ -228,11 +228,11 @@ def test_poll_skips_devices_without_entity_id(ha_app, ha_client_f):
 
 def test_poll_handles_api_error_gracefully(ha_app, ha_client_f):
     """When get_state returns None, no exception is raised and percentage stays None."""
-    ha_client_f.post("/device/add", data={"name": "Dev D", "battery_slots": "1"})
+    ha_client_f.post("/device/add", data={"name": "Dev D", "battery_slots": "1", "battery_size": "AA"})
     ha_client_f.post("/battery/add", data={"brand": "X", "count": "1"})
     ha_client_f.post("/battery/1/assign", data={"device_id": "1"})
     ha_client_f.post("/device/1/edit", data={
-        "name": "Dev D", "battery_slots": "1", "ha_entity_id": "sensor.dev_d"
+        "name": "Dev D", "battery_slots": "1", "battery_size": "AA", "ha_entity_id": "sensor.dev_d"
     })
 
     from ha_client import HomeAssistantClient
@@ -343,29 +343,29 @@ def test_retired_battery_excluded_from_needs_attention_section(ha_app, ha_client
 
 
 def test_device_detail_shows_ha_field(ha_client_f):
-    ha_client_f.post("/device/add", data={"name": "Dev E", "battery_slots": "1"})
+    ha_client_f.post("/device/add", data={"name": "Dev E", "battery_slots": "1", "battery_size": "AA"})
     resp = ha_client_f.get("/device/1")
     assert resp.status_code == 200
     assert b"ha_entity_id" in resp.data
 
 
 def test_edit_device_ha_entity_id_saves(ha_client_f):
-    ha_client_f.post("/device/add", data={"name": "Dev F", "battery_slots": "1"})
+    ha_client_f.post("/device/add", data={"name": "Dev F", "battery_slots": "1", "battery_size": "AA"})
     ha_client_f.post("/device/1/edit", data={
-        "name": "Dev F", "battery_slots": "1", "ha_entity_id": "sensor.my_remote"
+        "name": "Dev F", "battery_slots": "1", "battery_size": "AA", "ha_entity_id": "sensor.my_remote"
     })
     resp = ha_client_f.get("/device/1")
     assert b"sensor.my_remote" in resp.data
 
 
 def test_edit_device_ha_entity_id_clear(ha_client_f):
-    ha_client_f.post("/device/add", data={"name": "Dev G", "battery_slots": "1"})
+    ha_client_f.post("/device/add", data={"name": "Dev G", "battery_slots": "1", "battery_size": "AA"})
     ha_client_f.post("/device/1/edit", data={
-        "name": "Dev G", "battery_slots": "1", "ha_entity_id": "sensor.foo"
+        "name": "Dev G", "battery_slots": "1", "battery_size": "AA", "ha_entity_id": "sensor.foo"
     })
     # Now clear it
     ha_client_f.post("/device/1/edit", data={
-        "name": "Dev G", "battery_slots": "1", "ha_entity_id": ""
+        "name": "Dev G", "battery_slots": "1", "battery_size": "AA", "ha_entity_id": ""
     })
     resp = ha_client_f.get("/device/1")
     assert b"sensor.foo" not in resp.data
@@ -415,11 +415,11 @@ def test_manual_battery_percentage_edit(ha_client_f):
 
 def test_poll_skips_update_when_percentage_unchanged(ha_app, ha_client_f):
     """No write and no pct_log entry when the polled value matches the stored value."""
-    ha_client_f.post("/device/add", data={"name": "Dev NoCh", "battery_slots": "1"})
+    ha_client_f.post("/device/add", data={"name": "Dev NoCh", "battery_slots": "1", "battery_size": "AA"})
     ha_client_f.post("/battery/add", data={"brand": "X", "count": "1"})
     ha_client_f.post("/battery/1/assign", data={"device_id": "1"})
     ha_client_f.post("/device/1/edit", data={
-        "name": "Dev NoCh", "battery_slots": "1", "ha_entity_id": "sensor.noch"
+        "name": "Dev NoCh", "battery_slots": "1", "battery_size": "AA", "ha_entity_id": "sensor.noch"
     })
 
     from sqlalchemy import create_engine
@@ -446,11 +446,11 @@ def test_poll_skips_update_when_percentage_unchanged(ha_app, ha_client_f):
 
 def test_poll_creates_pct_log_on_change(ha_app, ha_client_f):
     """A pct_log entry with source='poll' is written when the value changes."""
-    ha_client_f.post("/device/add", data={"name": "Dev Chg", "battery_slots": "1"})
+    ha_client_f.post("/device/add", data={"name": "Dev Chg", "battery_slots": "1", "battery_size": "AA"})
     ha_client_f.post("/battery/add", data={"brand": "X", "count": "1"})
     ha_client_f.post("/battery/1/assign", data={"device_id": "1"})
     ha_client_f.post("/device/1/edit", data={
-        "name": "Dev Chg", "battery_slots": "1", "ha_entity_id": "sensor.chg"
+        "name": "Dev Chg", "battery_slots": "1", "battery_size": "AA", "ha_entity_id": "sensor.chg"
     })
 
     from ha_client import HomeAssistantClient
@@ -519,9 +519,9 @@ def test_manual_edit_no_log_when_unchanged(ha_client_f):
 
 def test_device_detail_shows_live_pct(ha_app, ha_client_f):
     """Opening a device page fetches live % from HA and displays it."""
-    ha_client_f.post("/device/add", data={"name": "Dev Live", "battery_slots": "1"})
+    ha_client_f.post("/device/add", data={"name": "Dev Live", "battery_slots": "1", "battery_size": "AA"})
     ha_client_f.post("/device/1/edit", data={
-        "name": "Dev Live", "battery_slots": "1", "ha_entity_id": "sensor.live_test"
+        "name": "Dev Live", "battery_slots": "1", "battery_size": "AA", "ha_entity_id": "sensor.live_test"
     })
 
     mock_resp = MagicMock()
@@ -537,11 +537,11 @@ def test_device_detail_shows_live_pct(ha_app, ha_client_f):
 
 def test_device_detail_updates_battery_on_load(ha_app, ha_client_f):
     """Battery percentage is updated (with pct_log) when device page is loaded and value changed."""
-    ha_client_f.post("/device/add", data={"name": "Dev Update", "battery_slots": "1"})
+    ha_client_f.post("/device/add", data={"name": "Dev Update", "battery_slots": "1", "battery_size": "AA"})
     ha_client_f.post("/battery/add", data={"brand": "X", "count": "1"})
     ha_client_f.post("/battery/1/assign", data={"device_id": "1"})
     ha_client_f.post("/device/1/edit", data={
-        "name": "Dev Update", "battery_slots": "1", "ha_entity_id": "sensor.update_test"
+        "name": "Dev Update", "battery_slots": "1", "battery_size": "AA", "ha_entity_id": "sensor.update_test"
     })
 
     mock_resp = MagicMock()