About this replacement
Motorola A760 / V300 / V500 Series — 3.7V Li-ion Replacement Battery (SNN5683A)
This is a 3.7V, 850mAh Li-ion cell that fits the Motorola A760 flip phone and its related V-series handsets including the V300, V400, and V500. It replaces OEM part numbers SNN5683A, SNN5683, SNN5717, and SNN5704. Dimensions are 57 × 35 × 4mm — confirm these against your existing cell before installing.
- A760 and V-series compatibility: These handsets share the same battery bay dimensions, connector pinout, and BMS communication protocol across the platform. One cell covers the full group — no hardware modification required.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the A760 platform. The BMS handshake completed on first connection, charge termination triggered correctly at full capacity, and no thermal events occurred during the charge cycle.
- Fuel gauge recalibration on first use: After installing this cell, run one complete discharge to near-empty, then charge to 100% without interruption. The A760's fuel gauge IC calibrates its coulomb counter against this first full cycle — skipping it causes the percentage display to read inaccurately for several days.
Sudden shutdown at 20–30% on the A760 after a cell swap
The A760's fuel gauge IC was calibrated to the discharge curve of the original aged cell, not a fresh one. A new 850mAh cell has a steeper voltage drop at the bottom of its curve than a degraded cell does. When the phone hits that voltage cliff — typically around 3.5–3.6V under GSM transmit load — the IC interprets it as empty and shuts down, even though the display showed 25%. One full discharge-charge cycle resets the coulomb counter and eliminates this behaviour.
Phone not powering on after the replacement cell sat in storage
Li-ion cells self-discharge during storage. If this battery dropped below approximately 2.5V per cell before installation, the BMS may have entered lockout mode to prevent damage. The A760 will show no response at all — no boot screen, no charge indicator. Connect the phone to a charger and leave it for 15–20 minutes before attempting to power on; most BMS circuits require a trickle-charge recovery period before they re-enable the main discharge path.