LG EG880 Replacement Battery 3.7V 800mAh Li-ion

LG EG880 / G5400 / G5410 — 3.7V Li-ion Replacement Battery

This is a 3.7V, 800mAh Li-ion battery for the LG EG880, G5400, and G5410 candybar-style mobile phones. It fits when the original cell can no longer hold a usable charge. Dimensions are 61.04 × 42.25 × 6.37mm — confirm against your original before installing.

• EG880, G5400, G5410 platform fit: These three models share the same battery bay dimensions, connector pinout, and 3.7V nominal voltage rail. One cell covers all three without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the bench. The BMS held cutoff correctly at both ends — no overcharge trip, no premature low-voltage lockout under screen-on load.
• Fuel gauge recalibration on first use: On first installation, run one complete discharge down to automatic shutoff, then charge uninterrupted to 100%. The phone's fuel gauge IC is still mapped to the old cell's discharge curve — skipping this step will cause the percentage readout to drift or jump until it recalibrates.

Sudden shutdown at 20–30% on the replacement cell

This happens when the fuel gauge IC hasn't recalibrated to the new cell's actual discharge curve. The phone sees a voltage drop it wasn't expecting at that state-of-charge level and triggers an emergency shutoff. It isn't a fault with the battery — it's the coulomb counter working off stale reference data. Run one full discharge-to-shutoff cycle followed by a full uninterrupted charge, and the shutoffs will stop.

Phone warm near the battery compartment on the first charge

A new Li-ion cell has higher internal impedance than a broken-in cell. During the first charge cycle, the charge IC pushes current into a cell that resists more than the old one did — that resistance converts to heat. The warmth is localised to the battery compartment and tapers off after the first full cycle. If the phone stays hot or the compartment becomes uncomfortable to touch, stop charging and check that the replacement cell is seated flat with no gap at the contacts.