Nokia Lumia 920 Replacement Battery BP-4GW 3.7V 2000mAh

Nokia Lumia 920 Series — 3.7V Li-Polymer Replacement Battery (BP-4GW)

This is a 3.7V, 2000mAh Li-Polymer replacement battery for the Nokia Lumia 920, Lumia 920T, Lumia 920.2, and Phi. It uses OEM part number BP-4GW and slots directly into the phone's sealed battery bay. Voltage and capacity match the original cell specification exactly.

• Lumia 920 family compatibility: The 920, 920T, 920.2, and Phi all share the same physical footprint, connector pinout, and 3.7V nominal voltage rail — which is why a single BP-4GW cell covers all four variants without any wiring or connector changes.
• Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on a Lumia 920 unit. The BMS accepted charge handshake immediately, held cutoff at 4.2V at top of charge, and the low-voltage protection tripped correctly at the 3.0V floor — no false shutdowns during the test sequence.
• Fuel gauge recalibration on first use: After fitting this cell, disable fast charging and complete one full discharge-to-charge cycle before heavy use. The Lumia 920's fuel gauge IC is calibrated to the old cell's discharge curve — one full cycle lets it remap against the new cell before the coulomb counter locks in its reference points.

Why the Lumia 920 reports wrong battery percentage after a cell swap

The Lumia 920 uses a coulomb-counting fuel gauge IC that builds its capacity model from the original cell's discharge curve over dozens of cycles. Swap in a new cell and that learned model no longer matches actual cell behaviour — so percentage readouts drift, sometimes badly. The fix is one complete discharge down to auto-shutdown, followed by a full charge to 100% without interruption. After that cycle, the IC resets its reference baseline against the new cell and percentage readings stabilise.

Sudden shutdown at 20–30% remaining on the replacement cell

This happens when the cell voltage drops sharply under high-current load — typically when the LTE modem ramps up or the screen drives peak backlight. A fresh Li-Polymer cell at 3.5V can collapse below the BMS cutoff threshold under that spike before the fuel gauge has time to update its display. It reads 25% one second and the phone is off the next. Run the phone through two full discharge-charge cycles to let the fuel gauge IC tighten its voltage-to-capacity mapping, and check that the reported percentage at shutdown is sitting above 3.4V under the Settings battery screen before calling it a fault.