diff --git a/tests/test_acceptance.py b/tests/test_acceptance.py
index 6e10acb..096541d 100644
--- a/tests/test_acceptance.py
+++ b/tests/test_acceptance.py
@@ -1216,3 +1216,113 @@ def test_device_charge_all_parent_no_installed(client):
     )
     assert resp.status_code == 200
     assert b"No installed batteries" in resp.data
+
+
+# ------------------------------------------------------------------ #
+# Battery — unretire
+# ------------------------------------------------------------------ #
+
+def test_unretire_battery(seeded_client):
+    # id=3 is retired by fixture
+    resp = seeded_client.post("/battery/3/unretire", follow_redirects=True)
+    assert resp.status_code == 200
+    assert b"now available again" in resp.data
+    assert b"available" in seeded_client.get("/battery/3").data.lower()
+
+
+def test_unretire_not_retired(seeded_client):
+    resp = seeded_client.post("/battery/1/unretire", follow_redirects=True)
+    assert b"is not retired" in resp.data
+
+
+# ------------------------------------------------------------------ #
+# Logbook
+# ------------------------------------------------------------------ #
+
+def test_battery_logbook_add_and_delete(seeded_client):
+    resp = seeded_client.post("/battery/1/logbook/add",
+                              data={"body": "Swapped terminals"}, follow_redirects=True)
+    assert b"Swapped terminals" in resp.data
+    resp = seeded_client.post("/battery/1/logbook/1/delete", follow_redirects=True)
+    assert b"Logbook entry deleted" in resp.data
+    assert b"Swapped terminals" not in seeded_client.get("/battery/1").data
+
+
+def test_battery_logbook_add_empty_body(seeded_client):
+    resp = seeded_client.post("/battery/1/logbook/add",
+                              data={"body": "  "}, follow_redirects=True)
+    assert b"Entry text is required" in resp.data
+
+
+def test_device_logbook_add_and_delete(seeded_client):
+    resp = seeded_client.post("/device/1/logbook/add",
+                              data={"body": "Cleaned contacts"}, follow_redirects=True)
+    assert b"Cleaned contacts" in resp.data
+    resp = seeded_client.post("/device/1/logbook/1/delete", follow_redirects=True)
+    assert b"Logbook entry deleted" in resp.data
+    assert b"Cleaned contacts" not in seeded_client.get("/device/1").data
+
+
+def test_device_logbook_add_empty_body(seeded_client):
+    resp = seeded_client.post("/device/1/logbook/add",
+                              data={"body": ""}, follow_redirects=True)
+    assert b"Entry text is required" in resp.data
+
+
+# ------------------------------------------------------------------ #
+# Charge log — delete
+# ------------------------------------------------------------------ #
+
+def test_charge_log_delete_reverts_cycles(seeded_client):
+    seeded_client.post("/battery/1/charge-log/add",
+                       data={"charged_date": "2026-06-01", "increment_cycles": "1"})
+    data = _json.loads(seeded_client.get("/export/all.json").data)
+    assert next(b for b in data["batteries"] if b["id"] == 1)["charge_cycles"] == 1
+    log_id = data["charge_logs"][0]["id"]
+    resp = seeded_client.post(f"/battery/1/charge-log/{log_id}/delete",
+                              follow_redirects=True)
+    assert b"Charge log entry deleted" in resp.data
+    data = _json.loads(seeded_client.get("/export/all.json").data)
+    assert next(b for b in data["batteries"] if b["id"] == 1)["charge_cycles"] == 0
+    assert data["charge_logs"] == []
+
+
+# ------------------------------------------------------------------ #
+# CSV exports
+# ------------------------------------------------------------------ #
+
+def test_csv_export_routes(seeded_client):
+    expectations = {
+        "/export/batteries.csv": b"label",
+        "/export/devices.csv": b"parent_id,parent_name",
+        "/export/charge-logs.csv": b"charged_date",
+        "/export/capacity-tests.csv": b"tested_capacity_mah",
+        "/export/pct-logs.csv": b"percentage",
+    }
+    for url, marker in expectations.items():
+        resp = seeded_client.get(url)
+        assert resp.status_code == 200, url
+        assert "text/csv" in resp.content_type, url
+        assert marker in resp.data, url
+    resp = seeded_client.get("/export/csv.zip")
+    assert resp.status_code == 200
+    assert "zip" in resp.content_type
+
+
+# ------------------------------------------------------------------ #
+# Sub-component edit — type/location stay NULL
+# ------------------------------------------------------------------ #
+
+def test_subcomponent_edit_resave_keeps_nulls(client):
+    _setup_rc_car(client)
+    # device 2 = Remote, sub-component of 1; re-save smuggling in type/location
+    resp = client.post("/device/2/edit", data={
+        "name": "Remote", "battery_slots": "2", "parent_id": "1",
+        "device_type": "Toy", "location": "Garage", "battery_size": "AA",
+    }, follow_redirects=True)
+    assert resp.status_code == 200
+    data = _json.loads(client.get("/export/all.json").data)
+    rem = next(d for d in data["devices"] if d["name"] == "Remote")
+    assert rem["parent_id"] is not None
+    assert rem["device_type"] is None
+    assert rem["location"] is None