LGIP-430A Replacement Battery for LG KU380 3.7V 650mAh

LG KU380 / KP100 / CB630 Series — 3.7V Li-ion Replacement Battery (LGIP-430A)

This is a 3.7V, 650mAh Li-ion replacement battery for the LG KU380 and a range of LG handsets sharing the same battery platform. It replaces OEM part numbers LGIP-430A, LGIP-431A, SBPL0089901, SBPL0083509, SBPL0092202, SBPL0092203, SBPL0093301, SBPL0093402, and SBPL0096602. Fit models include the KU380, KP100, CE110, and CB630, among others.

• KU380 / KP100 / CB630 platform compatibility: These models share a common 3.7V single-cell Li-ion battery bay, identical connector pinout, and the same BMS communication protocol. That's why one cell covers the full group — the charge IC and fuel gauge IC on each device recognise the same BMS handshake.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on a KU380 and monitored the BMS response. The protection circuit tripped correctly at low-voltage cutoff, and the charge IC accepted the cell without error flags on the first cycle.
• Fuel gauge recalibration on first use: On first installation, disable any fast-charge mode and run one complete discharge-charge cycle before normal use. The fuel gauge IC calibrates its discharge curve against the new cell during this cycle — skipping it leaves the coulomb counter mapped to the old cell and causes inaccurate percentage readings.

Why the KU380 reports wrong battery percentage after a cell swap

The KU380 uses a fuel gauge IC that builds its charge estimate from the previous cell's discharge curve. When a new cell goes in, that stored curve no longer matches actual cell behaviour. The IC keeps reporting against the old profile until it completes at least one full discharge-charge cycle with the new cell. Until recalibration finishes, the displayed percentage can read 20–30% higher or lower than reality. Run the phone down to automatic shutdown, then charge uninterrupted to 100% — after that single cycle, the gauge tracks correctly.

Sudden shutdown at 20–25% on the replacement cell

This happens when the cell voltage drops sharply under load — the modem radio and display together can pull enough current to cause a rapid voltage sag that triggers the BMS undervoltage cutoff before the fuel gauge reaches 0%. It is more pronounced on a new cell that has not yet completed a break-in cycle, because cell impedance is slightly higher out of the box. After one or two full discharge-charge cycles, internal impedance drops and the voltage sag under load becomes less severe. If shutdowns continue past three full cycles, check that the battery contacts are clean and making firm contact — a high-resistance connection amplifies the voltage drop under load.