BL-T24 LG K220 Replacement Battery 3.85V 4100mAh

LG K220 Series — 3.85V Li-Polymer Replacement Battery (BL-T24)

This is a 3.85V, 4100mAh Li-Polymer battery replacing OEM part BL-T24. It fits the LG K220, K220Y, K220Z, K220dsZ, and related variants. Physical dimensions are 102.60 × 45.90 × 5.20mm — confirm clearance before fitting if your unit has had a prior repair.

• K220 series compatibility: The K220 family shares the same battery bay geometry, BL-T24 connector pinout, and charge IC handshake across regional variants — K220Y, K220Z, and K220dsZ all draw from the same voltage rail at the same charge termination point.
• Bench tested on actual hardware: We cycled this cell through full charge and load discharge on K220 hardware. The BMS terminated charge correctly at 4.35V and tripped undervoltage cutoff cleanly without latching — no force-reset required to recover the cell after deep discharge testing.
• Fuel gauge recalibration on first cycle: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle. The fuel gauge IC calibrates its coulomb counter against the new cell's discharge curve — skipping this step causes the percentage readout to drift noticeably in the first week of use.

Sudden shutdown at 20–30% on the K220 after a cell swap

This is a voltage cliff issue, not a capacity problem. When the modem transmits or the screen brightness spikes, current draw causes a new cell's terminal voltage to sag faster than the fuel gauge IC expects — the phone hits its low-voltage cutoff while the gauge still reads 20–30%. One full discharge cycle lets the IC map the actual discharge curve of the replacement cell. After that cycle, shutdown behaviour aligns with the displayed percentage.

Phone warm near the battery during the first few charges

A new Li-Polymer cell has slightly higher internal impedance than a broken-in cell. The charge IC pushes the same constant-current rate into higher resistance, generating more heat in the first two to three cycles. This is normal and self-corrects as the cell's impedance drops with use. If warmth persists past the fifth charge cycle or the phone becomes hot rather than warm, check that the adhesive pull-tab was not crimped against the cell during reassembly — that can create a pressure point that affects thermal dissipation.