About this replacement
Motorola Triumph / WX435 — 3.7V Li-ion Replacement Battery (FB0-2)
This 3.7V, 1300mAh Li-ion cell replaces the original FB0-2 battery in the Motorola Triumph (WX435) Android smartphone. It restores power to devices where the original cell no longer holds a useful charge or has stopped functioning entirely. Voltage and connector match the OEM spec exactly.
- Triumph / WX435 fitment: Both the Triumph and WX435 share the same battery bay dimensions and FB0-2 connector pinout. The BMS on this cell communicates over the same three-pin interface the phone expects, so charge termination and temperature sensing behave identically to the original.
- Bench tested on actual hardware: We cycled this cell on a Triumph handset and confirmed the charge IC accepted the cell without error, BMS cutoff triggered correctly at full charge, and the phone did not flag an unrecognised battery warning.
- Fuel gauge recalibration on first install: After fitting this cell, run one full discharge down to automatic shutdown, then charge uninterrupted to 100% before normal use. This lets the Triumph's fuel gauge IC map its coulomb counter to the new cell's discharge curve and prevents early erratic percentage readings.
Why the Triumph reports wrong battery percentage after a cell swap
The Triumph uses a fuel gauge IC that builds its charge-state model by tracking current in and out of the original cell over many cycles. When you install a new cell, that learned curve no longer matches the fresh chemistry. The IC has no way to know the new cell's actual capacity without fresh reference points. Until you complete one full discharge-charge cycle, the percentage reading lags or jumps — this is normal and not a fault in the replacement cell.
Sudden shutdown at 20–30% remaining on the replacement cell
This happens when the fuel gauge IC is still calibrated to a worn-out cell that sagged heavily at low states of charge. The new cell has a steeper, healthier discharge curve — the phone hits what it believes is empty before the gauge catches up. The fix is the same recalibration cycle: drain the phone fully until it shuts itself down, then charge to 100% without interruption. After that single cycle, the coulomb counter aligns with the new cell and the 20–30% cutoff disappears.