About this replacement
LG KE770 / KF510 Series — 3.7V Li-ion Replacement Battery (LGIP-410A)
This is a 3.7V, 550mAh Li-ion replacement cell for the LG KE770 flip phone and related models including the KG289, 278A, and KF510. It slots into the original battery bay and uses the same three-contact connector as the LGIP-410A. Capacity is 550mAh — identical to the factory spec.
- KE770 / KG289 / KF510 platform fit: These models share the same battery bay dimensions, 3.7V voltage rail, and three-pin connector layout. One cell covers the full group without adapter or modification.
- Bench tested on actual hardware: We cycled this cell through full charge and discharge on the KE770 platform. The BMS accepted charge current immediately on first insertion, and protection circuits triggered correctly at low-voltage cutoff without requiring a manual reset.
- Fuel gauge recalibration on first install: After fitting this cell, run one complete discharge down to auto-shutdown, then charge uninterrupted to 100%. The phone's fuel gauge IC was calibrated to the old cell's discharge curve — skipping this step causes the percentage indicator to read inaccurately for the first several cycles.
Why the KE770 reports wrong battery percentage after a cell swap
The KE770 uses a basic fuel gauge IC that tracks capacity by mapping voltage against a stored discharge curve from the original cell. A new cell has a slightly different internal resistance and discharge profile, so the stored curve no longer matches. The phone reads voltage correctly but converts it to the wrong percentage. One full discharge-to-shutdown followed by a complete uninterrupted charge resets the reference points the IC uses for future reads.
Sudden shutdown at 20–30% on the new cell
This happens when the cell voltage drops sharply under the load spike from an outgoing call or backlight burst — a voltage cliff that the fuel gauge doesn't predict from the resting voltage. It's more common on a new cell before the fuel gauge IC has completed its first calibration cycle. Run the phone down to auto-shutdown once rather than topping up from 50%. After that first full cycle, the IC recalculates the cliff point and shutdown warnings appear at the correct percentage.