About this replacement
Nokia 8110 4G / 2720 Flip — 3.7V Li-ion Replacement Battery (BV-6A)
This is a 3.7V, 1200mAh Li-ion replacement cell for the Nokia 8110 4G and 2720 Flip. It fits models TA-1048 and TA-1059, along with two additional variants sharing the same BV-6A specification. If your original battery no longer holds a charge or the phone shuts down unexpectedly, this cell replaces it directly.
- 8110 4G and 2720 Flip compatibility: Both handsets share the BV-6A form factor, connector pinout, and 3.7V nominal voltage rail. The BMS handshake is identical across TA-1048, TA-1059, and the additional listed variants, so no firmware or hardware workaround is needed.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the 8110 4G platform. The BMS accepted the new cell without error flags, and charge termination triggered correctly at full capacity.
- Fuel gauge recalibration on first cycle: On first use after installation, run one complete discharge down to automatic shutdown, then charge to 100% uninterrupted. This gives the fuel gauge IC a full reference curve against the new cell before normal use begins — skipping this step is the main reason percentage readings drift early on.
Why the Nokia 8110 4G reports wrong battery percentage after a cell swap
The 8110 4G uses a fuel gauge IC that builds its capacity model from accumulated charge and discharge history. When you swap the cell, the IC still holds the old cell's discharge curve in memory. It maps voltage readings against that stale curve, so the percentage shown on screen doesn't match actual charge state. One full discharge-to-shutdown followed by an uninterrupted charge to 100% forces the IC to write a new reference curve. After that single cycle, percentage accuracy tightens up considerably.
Sudden shutdown at 20–30% on the replacement cell
This happens when the cell voltage drops sharply under modem or screen load — a voltage cliff the fuel gauge didn't predict because it hadn't yet mapped the new cell's discharge curve. The phone reads 25% on the gauge, but actual cell voltage under load falls below the protection threshold and the BMS cuts power. It's not a faulty cell. Complete the first full discharge-charge cycle described above, and the shutdowns stop once the IC recalibrates. If shutdowns persist past two full cycles, check that the battery connector is fully seated — a loose contact raises internal resistance and makes voltage sag worse under load.