Lark Bjorn LARK SP-220 Replacement Battery 3.7V 1000mAh

Lark Bjorn SP-220 / SP-230 Dual SIM — 3.7V Li-ion Replacement Battery

This 3.7V Li-ion cell replaces the internal battery in the Lark SP-220, SP-220 Dual, SP-230 Dual, and SP-230 Dual SIM smartphones. Capacity is 1000mAh (3.7Wh). The cell dimensions are 53.00 × 33.90 × 5.70mm — measure your original before ordering if you are unsure.

• SP-220 and SP-230 Dual SIM platform: Both the single-SIM SP-220 and dual-SIM SP-230 variants share the same battery bay dimensions and voltage rail. The connector pinout and BMS handshake are consistent across the series, so one cell covers all four listed models.
• Bench tested on actual hardware: We ran this cell through charge-discharge cycles and confirmed the BMS communicates correctly with the fuel gauge IC. Charge acceptance was stable from 3.0V up to the 4.2V cutoff, and the protection circuit tripped correctly at overdischarge.
• Fuel gauge recalibration on first use: After fitting this cell, disable fast charging for the first complete discharge-charge cycle. The phone's fuel gauge IC was calibrated to the old cell's discharge curve. One full cycle at standard current lets it recalibrate before high-current charging is applied to an uncalibrated cell.

Sudden shutdown at 20–30% on the SP-220 after a cell swap

The SP-220's modem and display draw current in short, sharp spikes. A fresh Li-ion cell with slightly higher internal impedance than the worn original can fail to hold voltage under those spikes, even at 25% reported charge. The fuel gauge IC reads voltage, not coulombs, so it reports 25% right up until the cell voltage collapses under load. One full calibration cycle — full discharge to auto-off, then full charge uninterrupted — typically narrows that gap. If shutdowns continue past three cycles, check the cell resting voltage under no load; it should read above 3.6V at the point of shutdown.

Phone warm near the battery compartment during the first few charges

A new Li-ion cell has higher impedance than a cell that has been cycled. The charge IC pushes current into that higher resistance, and the difference appears as heat. On the SP-220 this is most noticeable in the lower-rear area where the battery sits close to the back cover. It typically reduces after three to five cycles as the cell's impedance settles. If the device feels hot to the touch — not just warm — stop the charge and let the phone cool to room temperature before resuming.