About this replacement
Emporia TELME E1000 / E1200 — 3.7V Li-ion Replacement Battery (BAT-E1200)
This is a 3.7V, 1200mAh (4.44Wh) Li-ion cell for the Emporia TELME E1000 and TELME E1200. It fits both models directly — same connector, same physical footprint at 52 × 42 × 6mm. If the original cell no longer holds a charge through a normal day of calls and texts, this cell restores full capacity.
- TELME E1000 and E1200 compatibility: Both models use the same battery bay dimensions and the same two-pin connector with no BMS handshake between models. A single cell covers both. The AK-E1200 part number also applies to compatible third-party units using this footprint.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the TELME platform and confirmed the BMS accepted the cell without reporting fault codes. Voltage held steady across light-draw tasks — screen on, call active, standby.
- Fuel gauge recalibration on first use: After fitting this cell, let it drain to automatic shutdown once before recharging fully. The TELME's fuel gauge IC was calibrated to your old cell's discharge curve. One full cycle resets it to the new cell — after that, the percentage reading tracks accurately.
Why the TELME E1000 shows wrong battery percentage after a cell swap
The TELME uses a simple coulomb-counting fuel gauge IC. That IC builds its capacity model over charge cycles against the original cell's impedance and discharge curve. A new cell has different internal resistance — the gauge doesn't know that yet. Until you run one complete discharge-charge cycle, the percentage on screen reflects the old model, not the new cell. After that first full cycle, the IC re-anchors its zero and full points to the replacement cell's actual behaviour.
Sudden shutdown at 20–30% on the TELME after fitting a replacement cell
This is a voltage cliff problem, not a capacity problem. Under modem load — an active call or a signal search in a weak area — current draw spikes and cell voltage drops faster than the gauge predicts. If the gauge still thinks 30% maps to 3.5V but the new cell sags to 3.2V under that load, the protection circuit cuts power before the display has a chance to react. Fix this by running the phone through one full discharge to shutdown, then a full charge uninterrupted to 100%. That single cycle gives the fuel gauge IC the data it needs to map load-sag voltage correctly. Target: charge to 4.2V before trusting the percentage reading under call load.