About this replacement
Motorola V2188 / V3688 Series — 3.7V Li-ion Replacement Battery (SNN5341A)
This 3.7V, 900mAh Li-ion battery replaces the OEM pack on Motorola V2188, V3688, L2000, 2088, and over a dozen additional early-2000s Motorola GSM candybar handsets. It uses OEM part references SNN5341A and AANN4010A. The cell fits the original battery bay and connects to the same contact points without modification.
- Multi-model fit — V2188, V3688, L2000, 2088 and more: These Motorola handsets share the same 3.7V battery architecture, connector pinout, and BMS handshake protocol across the platform, which is why a single cell covers all of them. The PCB protection circuit communicates directly with the phone's charge IC using the same signal lines.
- Bench tested on actual hardware: We cycled this cell through full charge and discharge on a V2188 unit. The BMS accepted charge from the first connection, the over-discharge cutoff triggered correctly at the low-voltage threshold, and the protection circuit reset cleanly on reconnect without a fault state.
- Fuel gauge recalibration on first use: After installation, run one complete discharge down to auto-shutdown, then charge fully without interruption. The V2188's fuel gauge IC needs this cycle to map its coulomb counter against the new cell's actual discharge curve — skipping it causes the percentage readout to drift immediately.
Why the V2188 reports the wrong battery percentage after a cell swap
The V2188 uses a simple fuel gauge IC that tracks charge state by counting coulombs against a stored discharge curve. That curve was calibrated to the original cell's internal resistance and capacity. A new cell has different internal resistance — often lower — so the IC's calculations drift against the actual cell voltage. The phone may show 40% and shut down moments later, or show 15% and keep running. One full uninterrupted discharge-to-shutdown followed by a full charge resets the reference points the IC uses.
Sudden shutdown at 20–30% on the replacement cell
This happens when the GSM radio fires a high-current transmission burst and the cell voltage sags below the BMS cutoff threshold — even though the fuel gauge still shows charge remaining. The V2188's GSM transmitter draws sharp current spikes during active calls, and a cell that hasn't been through a calibration cycle yet will hit the BMS low-voltage trip point before the gauge catches up. Run the full calibration cycle first: one complete discharge to auto-shutdown, then charge to 100% at the standard wall rate. If the shutdowns continue after calibration, check that the battery contacts in the bay are clean and making full contact — measure resting voltage with a meter; it should read above 3.7V at a full charge state.