LGIP-570A Replacement Battery for LG KC550 3.7V 800mAh

LG KC550 / KF700 Series — 3.7V Li-ion Replacement Battery (LGIP-570A)

This is a 3.7V, 800mAh Li-ion cell built to the same form factor as the original LGIP-570A. It fits the LG KC550, KC550 Orsay, KF700, KC780, and eight additional models sharing the same battery bay and connector. Dimensions are 44.04 × 37.94 × 5.82mm — a direct physical match to the original.

• KC550 / KF700 platform compatibility: These models share the same 3.7V single-cell architecture, connector pinout, and BMS communication protocol. One cell fits the entire group without modification or adapter.
• Bench tested on actual hardware: We cycled this cell on the KC550 platform and confirmed the BMS accepted the new cell on first power-on, charge termination triggered correctly at 4.2V, and the protection circuit tripped at the correct low-voltage cutoff.
• Fuel gauge recalibration after install: The KC550 uses a basic coulomb counter tied to the original cell's discharge curve. After fitting this replacement, run one full discharge to near-shutdown, then charge uninterrupted to 100%. This resets the gauge to the new cell's actual curve and stops erratic percentage readings.

Why the KC550 reports wrong battery percentage after a cell swap

The KC550's fuel gauge IC stores a charge curve calibrated against the original cell. When a new cell goes in, the stored curve no longer matches actual cell behaviour, so the percentage display drifts — often reading 80% while the phone is close to shutdown. The fix is one complete discharge-charge cycle without interruption. After that cycle, the coulomb counter re-anchors to the new cell's voltage-to-capacity relationship and percentage accuracy returns to normal.

Phone shuts down suddenly at 20–30% with the replacement cell

This is a voltage cliff issue, not a capacity fault. Under screen or call load, the new cell's internal impedance causes a sharper voltage drop than the aged original the gauge was calibrated to. When the cell voltage dips below the BMS cutoff threshold — typically 3.0V under load — the phone shuts down even though the gauge still shows charge remaining. Run the full calibration cycle described above. If shutdown persists, check that the battery contacts are fully seated; a partial connection raises contact resistance and worsens voltage sag under load.