About this replacement
Motorola Moto X Style — 3.8V Li-Polymer Replacement Battery (FX30 / SNN5964A)
This is a 3.8V, 2800mAh lithium-polymer replacement battery for the Motorola Moto X Style, Moto X Pure Edition, X Style X+2, and XT1572. It slots into the same cell bay as the original FX30 and uses the same SNN5964A-spec BMS handshake. If your original cell no longer carries a full charge or the phone shuts down unexpectedly under load, this is the direct swap.
- Moto X Style / Pure Edition / XT1572 compatibility: These variants share the same 3.8V power rail, identical connector pinout, and the same fuel gauge IC protocol — so one cell revision covers all of them without adapter or firmware changes.
- Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on the XT1572 board. The BMS accepted the charge IC handshake on the first cycle and the fuel gauge IC tracked state-of-charge without error flags.
- First-cycle fuel gauge recalibration: After installation, disable fast charging and run one complete discharge-charge cycle at standard rate. The Moto X Style's coulomb counter was calibrated to the original cell's discharge curve — one full slow cycle resets that baseline before fast charge pushes high current into an uncalibrated cell.
Sudden shutdown at 20–30% on the Moto X Style after a cell swap
This happens because the fuel gauge IC still holds the old cell's voltage-to-capacity curve in memory. When the new cell's voltage drops faster under modem or display load than the IC expects, the phone reads 20–30% but the actual cell voltage has already hit the low-voltage cutoff threshold. The BMS trips and the phone shuts down to protect the cell. Run one full discharge to below 5% followed by a complete charge — this forces the coulomb counter to rebuild its curve against the new cell. After that cycle, the reported percentage tracks correctly.
Phone won't power on after sitting in storage for several months
Lithium-polymer cells that self-discharge below roughly 2.5V per cell trigger a BMS lockout — the protection circuit opens and blocks normal charging to prevent thermal runaway on a deeply depleted cell. The Moto X Style will show nothing on screen when you plug it in, which looks like a dead board but is usually just BMS lockout. Connect to a wall charger — not a USB port — and leave it for 20–30 minutes without pressing the power button. The charge IC delivers a low-current trickle that slowly recovers cell voltage; once it crosses approximately 3.0V the BMS re-closes and normal charging resumes.