Motorola KZ50 Moto G Power Compatible Battery 3.85V 4900mAh

Motorola Moto G Power — 3.85V Li-Polymer Replacement Battery (KZ50)

This is a 3.85V, 4900mAh (18.87Wh) lithium-polymer replacement battery for the Motorola Moto G Power. It fits models PAH30004, PAH30004US, and XT2041-7. The KZ50 cell slots directly into the battery bay and connects to the same BMS handshake points as the original.

• Moto G Power model coverage: PAH30004, PAH30004US, and XT2041-7 all share the same battery bay dimensions, connector pinout, and fuel gauge IC communication protocol — one cell fits all three without adapter or modification.
• Bench tested on actual hardware: We ran this cell on a Moto G Power unit and confirmed the BMS handshake completed on first boot, charge current ramped correctly through CC/CV stages, and the fuel gauge IC accepted the cell without throwing a battery-health error.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one full discharge-charge cycle at standard rate. This lets the fuel gauge IC map the new cell's discharge curve before high-current fast charging pushes load into an uncalibrated coulomb counter.

Sudden shutdown at 20–30% on the Moto G Power after a cell swap

The Moto G Power's fuel gauge IC was calibrated against the original cell's voltage-discharge curve. A new KZ50 cell has a slightly different impedance profile, so the IC miscalculates remaining capacity at low state-of-charge. When the display and modem draw peaks — scroll, call, or data burst — the cell voltage drops below the BMS cutoff threshold even though the OS still shows 20–30%. One full discharge-charge cycle at standard rate lets the coulomb counter relearn the curve and pushes the cutoff point back to where it belongs.

USB-PD fast charge not activating on the first cycle after replacement

After a cell swap, the charge IC sometimes defaults to slow-charge mode on the first cycle because the BMS has not yet validated the new cell's internal resistance against its fast-charge admission threshold. This is not a fault in the cable or adapter. Complete one full standard-rate charge to 100% before enabling fast charging again. After that cycle, fast charge should negotiate normally — if it still does not, check the charge port for debris before assuming a BMS fault.