diff --git a/app.py b/app.py
index e07fc99..1edeee8 100644
--- a/app.py
+++ b/app.py
@@ -77,14 +77,31 @@ def create_app(config_object="config"):
     # Battery — edit notes
     # ------------------------------------------------------------------ #
 
-    @app.route("/battery/<int:battery_id>/edit-notes", methods=["POST"])
-    def battery_edit_notes(battery_id):
+    @app.route("/battery/<int:battery_id>/edit-details", methods=["POST"])
+    def battery_edit_details(battery_id):
         battery = db.get(Battery, battery_id)
         if battery is None:
             abort(404)
-        battery.notes = request.form.get("notes", "").strip() or None
+        f = request.form
+
+        def _int(key):
+            v = f.get(key, "").strip()
+            try:
+                return int(v) if v else None
+            except ValueError:
+                return None
+
+        battery.notes               = f.get("notes", "").strip() or None
+        battery.size                = f.get("size", "").strip() or None
+        battery.chemistry           = f.get("chemistry", "").strip() or None
+        battery.capacity_mah        = _int("capacity_mah")
+        battery.tested_capacity_mah = _int("tested_capacity_mah")
+        battery.tested_date         = f.get("tested_date", "").strip() or None
+        battery.charge_cycles       = _int("charge_cycles")
+        battery.purchase_date       = f.get("purchase_date", "").strip() or None
+
         db.commit()
-        flash("Notes updated.", "success")
+        flash("Details updated.", "success")
         return redirect(url_for("battery_detail", battery_id=battery_id))
 
     # ------------------------------------------------------------------ #
diff --git a/models.py b/models.py
index 9b6e334..95110cd 100644
--- a/models.py
+++ b/models.py
@@ -37,6 +37,15 @@ class Battery(Base):
     device_id = Column(Integer, ForeignKey("device.id", ondelete="SET NULL"), nullable=True)
     notes = Column(Text, nullable=True)
 
+    # Optional metadata
+    size                = Column(String(20),  nullable=True)   # AA, AAA, 18650, CR2032 …
+    chemistry           = Column(String(20),  nullable=True)   # NiMH, Alkaline, Li-ion …
+    capacity_mah        = Column(Integer,     nullable=True)   # nominal capacity in mAh
+    tested_capacity_mah = Column(Integer,     nullable=True)   # last measured capacity in mAh
+    tested_date         = Column(String(10),  nullable=True)   # YYYY-MM-DD of last test
+    charge_cycles       = Column(Integer,     nullable=True)   # number of charge cycles
+    purchase_date       = Column(String(10),  nullable=True)   # YYYY-MM-DD when purchased
+
     device = relationship("Device", back_populates="batteries")
 
     def is_available(self):
diff --git a/templates/battery_detail.html b/templates/battery_detail.html
index 47b2d8f..634c82e 100644
--- a/templates/battery_detail.html
+++ b/templates/battery_detail.html
@@ -4,6 +4,15 @@
 {% block content %}
 <h1>{{ battery.label }}</h1>
 
+{% macro meta_row(label, value) %}
+{% if value %}
+<tr>
+  <td style="padding:0.3rem 1rem 0.3rem 0;font-weight:600;color:#64748b;border:none;">{{ label }}</td>
+  <td style="border:none;">{{ value }}</td>
+</tr>
+{% endif %}
+{% endmacro %}
+
 <div class="card">
   <table style="width:auto;border:none;">
     <tr>
@@ -28,17 +37,117 @@
         {% endif %}
       </td>
     </tr>
+    {{ meta_row("Size", battery.size) }}
+    {{ meta_row("Chemistry", battery.chemistry) }}
+    {% if battery.capacity_mah %}
+    <tr>
+      <td style="padding:0.3rem 1rem 0.3rem 0;font-weight:600;color:#64748b;border:none;">Capacity</td>
+      <td style="border:none;">
+        {{ battery.capacity_mah }} mAh
+        {% if battery.tested_capacity_mah %}
+          {% set pct = (battery.tested_capacity_mah / battery.capacity_mah * 100)|round|int %}
+          {% if pct >= 80 %}{% set health_color = "#166534" %}
+          {% elif pct >= 60 %}{% set health_color = "#92400e" %}
+          {% else %}{% set health_color = "#991b1b" %}
+          {% endif %}
+          &rarr; tested <strong style="color:{{ health_color }};">{{ battery.tested_capacity_mah }} mAh ({{ pct }}%)</strong>
+          {% if battery.tested_date %}<span class="text-muted">on {{ battery.tested_date }}</span>{% endif %}
+        {% endif %}
+      </td>
+    </tr>
+    {% elif battery.tested_capacity_mah %}
+    <tr>
+      <td style="padding:0.3rem 1rem 0.3rem 0;font-weight:600;color:#64748b;border:none;">Tested Capacity</td>
+      <td style="border:none;">
+        {{ battery.tested_capacity_mah }} mAh
+        {% if battery.tested_date %}<span class="text-muted">on {{ battery.tested_date }}</span>{% endif %}
+      </td>
+    </tr>
+    {% endif %}
+    {{ meta_row("Charge Cycles", battery.charge_cycles) }}
+    {{ meta_row("Purchase Date", battery.purchase_date) }}
+    {% if battery.notes %}
+    <tr>
+      <td style="padding:0.3rem 1rem 0.3rem 0;font-weight:600;color:#64748b;border:none;">Notes</td>
+      <td style="border:none;">{{ battery.notes }}</td>
+    </tr>
+    {% endif %}
   </table>
 </div>
 
-<!-- Notes -->
+<!-- Edit Details -->
 <div class="card">
-  <h2>Notes</h2>
-  <form method="post" action="{{ url_for('battery_edit_notes', battery_id=battery.id) }}">
-    <div class="form-group">
-      <textarea name="notes" placeholder="No notes yet…">{{ battery.notes or '' }}</textarea>
+  <h2>Edit Details</h2>
+  <form method="post" action="{{ url_for('battery_edit_details', battery_id=battery.id) }}">
+
+    <div style="display:grid;grid-template-columns:1fr 1fr;gap:0 1rem;">
+
+      <div class="form-group">
+        <label>Size</label>
+        <select id="size-select" onchange="metaSelectChanged(this,'size')">
+          <option value="">— none —</option>
+          {% for opt in ['AA','AAA','C','D','9V','18650','21700','14500','26650','CR2032','CR123A'] %}
+          <option value="{{ opt }}" {% if battery.size == opt %}selected{% endif %}>{{ opt }}</option>
+          {% endfor %}
+          <option value="__new__" {% if battery.size and battery.size not in ['AA','AAA','C','D','9V','18650','21700','14500','26650','CR2032','CR123A'] %}selected{% endif %}>Other…</option>
+        </select>
+        <input type="text" id="size" name="size" value="{{ battery.size or '' }}"
+               placeholder="Enter size"
+               style="display:{% if battery.size and battery.size not in ['AA','AAA','C','D','9V','18650','21700','14500','26650','CR2032','CR123A'] %}''{% else %}none{% endif %};margin-top:0.4rem;">
+      </div>
+
+      <div class="form-group">
+        <label>Chemistry</label>
+        <select id="chemistry-select" onchange="metaSelectChanged(this,'chemistry')">
+          <option value="">— none —</option>
+          {% for opt in ['NiMH','Alkaline','Li-ion','LiFePO4','NiCd','Zinc-Carbon','Li-MnO2'] %}
+          <option value="{{ opt }}" {% if battery.chemistry == opt %}selected{% endif %}>{{ opt }}</option>
+          {% endfor %}
+          <option value="__new__" {% if battery.chemistry and battery.chemistry not in ['NiMH','Alkaline','Li-ion','LiFePO4','NiCd','Zinc-Carbon','Li-MnO2'] %}selected{% endif %}>Other…</option>
+        </select>
+        <input type="text" id="chemistry" name="chemistry" value="{{ battery.chemistry or '' }}"
+               placeholder="Enter chemistry"
+               style="display:{% if battery.chemistry and battery.chemistry not in ['NiMH','Alkaline','Li-ion','LiFePO4','NiCd','Zinc-Carbon','Li-MnO2'] %}''{% else %}none{% endif %};margin-top:0.4rem;">
+      </div>
+
+      <div class="form-group">
+        <label for="capacity_mah">Capacity (mAh)</label>
+        <input type="number" id="capacity_mah" name="capacity_mah" min="0"
+               value="{{ battery.capacity_mah or '' }}" placeholder="e.g. 2000">
+      </div>
+
+      <div class="form-group">
+        <label for="charge_cycles">Charge Cycles</label>
+        <input type="number" id="charge_cycles" name="charge_cycles" min="0"
+               value="{{ battery.charge_cycles or '' }}" placeholder="e.g. 50">
+      </div>
+
+      <div class="form-group">
+        <label for="tested_capacity_mah">Tested Capacity (mAh)</label>
+        <input type="number" id="tested_capacity_mah" name="tested_capacity_mah" min="0"
+               value="{{ battery.tested_capacity_mah or '' }}" placeholder="e.g. 1850">
+      </div>
+
+      <div class="form-group">
+        <label for="tested_date">Test Date</label>
+        <input type="date" id="tested_date" name="tested_date"
+               value="{{ battery.tested_date or '' }}">
+      </div>
+
+      <div class="form-group">
+        <label for="purchase_date">Purchase Date</label>
+        <input type="date" id="purchase_date" name="purchase_date"
+               value="{{ battery.purchase_date or '' }}">
+      </div>
+
     </div>
-    <button class="btn btn-primary" type="submit">Save Notes</button>
+
+    <div class="form-group">
+      <label for="notes">Notes</label>
+      <textarea id="notes" name="notes" placeholder="No notes yet…">{{ battery.notes or '' }}</textarea>
+    </div>
+
+    <button class="btn btn-primary" type="submit">Save Details</button>
   </form>
 </div>
 
@@ -67,4 +176,18 @@
 </div>
 
 <a class="text-muted" href="{{ url_for('dashboard') }}">&larr; Back to Dashboard</a>
+
+<script>
+function metaSelectChanged(sel, inputId) {
+  var input = document.getElementById(inputId);
+  if (sel.value === '__new__') {
+    input.style.display = '';
+    input.value = '';
+    input.focus();
+  } else {
+    input.style.display = 'none';
+    input.value = sel.value;
+  }
+}
+</script>
 {% endblock %}
diff --git a/templates/dashboard.html b/templates/dashboard.html
index 5953047..89b29c0 100644
--- a/templates/dashboard.html
+++ b/templates/dashboard.html
@@ -51,6 +51,7 @@
             <th style="width:1.5rem;"><input type="checkbox" id="select-all" title="Select all"></th>
             <th>Label</th>
             <th>Brand</th>
+            <th>Size</th>
             <th>Status</th>
             <th>Assigned To</th>
             <th>Actions</th>
@@ -62,6 +63,7 @@
             <td><input type="checkbox" name="battery_ids" value="{{ b.id }}" class="row-cb"></td>
             <td><a href="{{ url_for('battery_detail', battery_id=b.id) }}"><strong>{{ b.label }}</strong></a></td>
             <td>{{ b.brand }}</td>
+            <td>{{ b.size or '—' }}</td>
             <td>
               <span class="badge badge-{{ b.status }}">{{ b.status|capitalize }}</span>
             </td>
@@ -94,7 +96,7 @@
             </td>
           </tr>
           {% else %}
-          <tr><td colspan="6" class="text-muted" style="text-align:center;padding:1rem;">No batteries found. <a href="{{ url_for('battery_add') }}">Add some.</a></td></tr>
+          <tr><td colspan="7" class="text-muted" style="text-align:center;padding:1rem;">No batteries found. <a href="{{ url_for('battery_add') }}">Add some.</a></td></tr>
           {% endfor %}
         </tbody>
       </table>
diff --git a/tests/test_acceptance.py b/tests/test_acceptance.py
index cecaeb6..56c201b 100644
--- a/tests/test_acceptance.py
+++ b/tests/test_acceptance.py
@@ -90,7 +90,7 @@ def test_battery_detail_not_found(client):
 # ------------------------------------------------------------------ #
 
 def test_edit_notes(seeded_client):
-    seeded_client.post("/battery/1/edit-notes", data={"notes": "test note here"})
+    seeded_client.post("/battery/1/edit-details", data={"notes": "test note here"})
     resp = seeded_client.get("/battery/1")
     assert b"test note here" in resp.data