About this replacement
Motorola XT882 / Droid 3 — 3.7V Li-ion Replacement Battery (BF6X)
This is a 3.7V, 1500mAh Li-ion replacement cell for the Motorola XT882 and its platform siblings. It fits the XT882, Droid 3, XT862, and Milestone 3, among others. OEM part numbers covered include BF6X, SNN5885, and SNN5885A.
- XT882 / Droid 3 platform fit: These models share the same battery bay dimensions, 3.7V voltage rail, and connector pinout. The BMS handshake protocol is identical across the platform, so one cell covers all listed variants without modification.
- Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on the XT882. The BMS accepted the cell without fault flags, charge termination triggered correctly at 4.2V, and the protection circuit tripped as expected under simulated short-circuit load.
- Fuel gauge recalibration after installation: On first use, disable fast charging if your charger supports it and run one complete discharge down to auto-shutoff, then charge fully without interruption. The XT882's fuel gauge IC calibrates its coulomb counter against the new cell's discharge curve on that first full cycle — skipping this step causes the percentage readout to drift for several days.
Sudden shutdown at 20–30% on the XT882 after a cell swap
This is a voltage cliff failure. Under peak modem load or screen-on brightness, the new cell's internal resistance briefly drops the voltage below the BMS cutoff threshold — even though the fuel gauge still shows 20–30%. The old cell's discharge curve was mapped into the fuel gauge IC, and the new cell's curve doesn't match it yet. One full calibration cycle — full discharge to shutoff, then uninterrupted charge to 100% — shifts the IC's reference curve and eliminates most cliff shutdowns. If it persists after two full cycles, check that the battery contacts in the bay are clean and making flush contact.
XT882 not powering on after the replacement battery sat in storage
If the cell voltage dropped below approximately 2.5V during storage, the BMS enters lockout mode to prevent charging a deeply discharged lithium cell. The phone will show nothing — no charging animation, no response. Connect it to a wall charger rated at least 1A and leave it for 20–30 minutes without pressing any buttons. Most BMS circuits include a trickle pre-charge path that slowly raises cell voltage back above the recovery threshold, after which normal charging resumes. If the device still shows no sign of life after 45 minutes on the wall charger, confirm the charger output with a multimeter — a 5V, 1A minimum is required to trigger pre-charge.