About this replacement
Nokia 105 2023 / 105 4G — 3.7V Li-ion Replacement Battery (BL-L5H)
This is a 3.7V, 1300mAh Li-ion replacement battery for the Nokia 105 2023, Nokia 105 4G, and variants TA-1385-DS and TA-1551. It uses OEM part number BL-L5H and matches the original cell's voltage rail and connector footprint. Capacity figures are taken directly from product data at 1300mAh (4.81Wh).
- 105 2023 and 105 4G compatibility: Both the 105 2023 and 105 4G share the BL-L5H form factor, voltage rail, and connector pinout. The BMS handshake on these variants expects the same 3.7V nominal cell — swapping between them requires no adapter or firmware change.
- Bench tested on actual hardware: We cycled this cell through full discharge and recharge on a Nokia 105 4G unit. The BMS accepted the cell without error flags, and charge termination triggered correctly at the expected cutoff voltage.
- Fuel gauge recalibration after swap: On first use, run one complete discharge down to automatic shutdown, then charge uninterrupted to 100% before using the phone again. This gives the coulomb counter a clean reference curve for the new cell and prevents early percentage drift.
Why the Nokia 105 reports wrong battery percentage after a cell swap
The 105's fuel gauge IC builds its percentage model from the discharge curve of the original cell. When a new cell goes in, that stored curve no longer matches actual cell behaviour. The gauge then reports percentages based on stale data — often reading 100% too quickly or dropping faster than the real charge level warrants. One full discharge-to-shutdown followed by a full uninterrupted charge resets the coulomb counter's baseline against the new cell. After that cycle, percentage readings stabilise.
Sudden shutdown at 15–25% on the replacement cell
This happens when the cell voltage drops sharply under load — the modem polling or screen burst draws current the cell can't sustain at low state of charge, and voltage collapses past the BMS cutoff threshold before the gauge reaches 0%. It is a voltage cliff, not a capacity fault with the replacement cell itself. The fix is to run two full discharge-charge cycles after installation so the fuel gauge recalibrates its low-voltage slope. If shutdowns persist past three cycles, check that the battery connector is fully seated — a loose contact raises effective impedance and worsens voltage sag.