LG Optimus M BL-53QH Replacement Battery 3.7V 1400mAh

MetroPCS LG Optimus M MS870 — 3.7V Li-ion Replacement Battery (BL-53QH)

This is a 3.7V 1400mAh Li-ion battery for the LG Optimus M running on MetroPCS 4G (model MS870 / LGMS870). It replaces part number BL-53QH and OEM reference EAC61878605. Fit the cell when the original no longer holds a charge through a normal day of use.

• MS870 and LGMS870 compatibility: Both model strings refer to the same LG Optimus M hardware on the MetroPCS 4G network. They share an identical battery bay, connector pitch, and BMS handshake protocol, so one cell covers both designations without modification.
• Bench tested on actual hardware: We cycled this cell through a full discharge and charge sequence on an MS870 unit. The BMS accepted the cell on first connection, charge termination triggered correctly at 4.2V, and the protection circuit tripped as expected at the low-voltage threshold — no manual reset needed.
• Fuel gauge recalibration on first cycle: Disable any fast-charge app or aggressive power mode during the very first complete discharge-to-charge cycle. The Optimus M's fuel gauge IC needs to read the new cell's actual discharge curve before it can report accurate percentages — running a full uninterrupted cycle gives it clean data to work from.

Sudden shutdown at 20–30% on the MS870 after a cell swap

The LG Optimus M's modem radio and display pull current spikes that the battery voltage cannot sustain if the fuel gauge IC is still calibrated to the old, degraded cell curve. When voltage sags below roughly 3.5V under load, the BMS cuts power before the reported percentage reaches zero — so the phone dies at 25% on the screen. This is not a fault with the replacement cell. One full uninterrupted discharge down to automatic shutdown, followed by a complete charge to 100%, resets the coulomb counter against the new cell's actual capacity. After that cycle, shutdowns at partial charge should stop.

Phone reports wrong battery percentage after fitting the BL-53QH

The MS870's fuel gauge IC stores a learned discharge profile from the previous battery. A new cell with different internal impedance throws off that learned curve immediately, causing the percentage readout to jump or stall at unexpected points. The fix is a single calibration cycle: drain the phone to automatic shutdown, then charge uninterrupted to 100% without removing the charger. The fuel gauge IC writes a new baseline from that run. If the percentage still drifts after one cycle, repeat the process once more — two full cycles resolve the majority of recalibration cases.