About this replacement
Lenovo S60 Series — 3.8V Li-Polymer Replacement Battery (BL245)
This is a 3.8V, 2150mAh Li-Polymer replacement battery for the Lenovo S60, S60-t, and S60-w smartphones. It replaces OEM part number BL245 and restores power to phones where the original cell has degraded. Capacity is rated at 8.17Wh.
- S60, S60-t, and S60-w fit: All three S60 variants share the same battery bay dimensions and BL245 connector pinout. The BMS handshake protocol is identical across the trio, so one cell covers the full model range without hardware modification.
- Bench tested on actual hardware: We cycled this cell through the S60 charge IC and monitored BMS communication at each charge stage. The protection circuit tripped correctly at the low-voltage cutoff and resumed charge without error after a standard reconnect.
- Fuel gauge recalibration on first use: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC recalibrate against the new cell's discharge curve before high-current charging pushes current into an uncalibrated cell.
Why the S60 reports wrong battery percentage after a cell swap
The S60 uses a coulomb counter in its fuel gauge IC that builds a model of the cell's discharge curve over time. When you swap the physical cell, the IC still holds the old cell's calibration data. The percentage readout pulls from that stale model, not the actual charge state of the new cell. One full discharge-to-empty followed by an uninterrupted charge to 100% forces the IC to rewrite its reference curve against the new BL245 cell.
Sudden shutdown at 20–30% on the replacement cell
This happens when the cell voltage drops sharply under load — screen-on combined with modem activity pulls enough current to cause a voltage cliff before the percentage gauge reaches zero. The BMS reads the voltage drop as a hard cutoff condition and shuts the phone down even though the fuel gauge still shows charge remaining. After the first full calibration cycle, the fuel gauge IC maps the new cell's actual voltage-to-capacity curve and the premature shutdowns stop. If shutdowns persist past two full cycles, check that the replacement cell contacts are seated flat with no gap at the connector.