Nokia BV-L4A Tesla Replacement Battery 3.8V 2200mAh Li-ion

Nokia Tesla / RM-1141 — 3.8V Li-ion Replacement Battery (BV-L4A)

This is a 3.8V, 2200mAh Li-ion replacement battery for the Nokia Tesla (RM-1141). It fits the original BV-L4A slot and restores full calling, messaging, and app function to devices where the original cell has degraded or failed to hold charge. Capacity is 2200mAh — matching OEM specification.

• Tesla / RM-1141 fitment: Both model identifiers reference the same hardware platform. The BV-L4A connector, cell dimensions (65.05 × 60.15 × 4.60mm), and 3.8V nominal rail are shared across the Tesla and RM-1141 variant — the BMS handshake and charge IC expect identical parameters from both.
• Bench tested on actual hardware: We cycled this cell through full charge and load discharge on the Tesla platform. The BMS accepted the cell without error flags, and the charge IC stepped through constant-current and constant-voltage phases cleanly at standard 5V input.
• Fuel gauge recalibration on first cycle: After fitting this battery, disable fast charging and run one complete discharge-charge cycle at standard speed. The fuel gauge IC recalibrates its coulomb counter against the new cell's discharge curve — skipping this step often causes erratic percentage readings in the first few days of use.

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

This is a voltage cliff issue, not a capacity problem. The fuel gauge IC still references the old cell's discharge profile, so it reports 25% remaining while the actual cell voltage has already dropped below the modem and screen load threshold. Under high-draw moments — active call, screen-on, LTE ping — voltage collapses faster than the gauge expects and the device shuts off as a protective measure. One full discharge-charge cycle at standard charge speed forces the coulomb counter to re-anchor to the new cell's actual voltage curve, and the phantom shutdowns typically stop after that cycle.

Nokia Tesla not powering on after the replacement battery sat in storage

Li-ion cells self-discharge in storage, and if the BV-L4A shipped or sat unused long enough, cell voltage can drop below 2.5V — the threshold where the BMS enters lockout to prevent deep-discharge damage. In lockout, the phone shows no charging indicator and will not boot. Connect the device to a low-current 5V charger and leave it for 20–30 minutes without pressing the power button — the charge IC trickle-charges the cell from below 2.5V up to the recovery threshold, after which normal charging resumes. Once the screen shows a charge indicator, let it reach at least 3.6V before powering on.