Infinix Smart BL-AW878 Replacement Battery 3.7V 2650mAh

Infinix Smart X5010 — 3.7V Li-Polymer Replacement Battery (BL-AW878)

The BL-AW878 is a 3.7V, 2650mAh lithium-polymer cell that fits the Infinix Smart (X5010). It restores power to a phone that no longer holds charge, drains overnight, or shuts off unexpectedly. Capacity and voltage match the original Infinix specification exactly.

• Infinix Smart X5010 fitment: The X5010 uses a fixed rear-cover design with a direct contact connector and a BMS that handshakes with the charge IC over a single thermistor line. This cell matches that connector pinout, voltage rail, and thermistor resistance profile.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the X5010 platform. The BMS accepted the cell without fault codes, and the charge IC completed a full constant-current to constant-voltage transition at 4.2V with no cutoff interruptions.
• Fuel gauge recalibration on first cycle: On first use after installation, disable fast charging and let the phone complete one full discharge-to-charge cycle at standard rate. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging begins — skipping this step causes percentage jumps and premature low-battery alerts.

Sudden shutdown at 20–30% on the replacement cell

This happens because the fuel gauge IC is still calibrated to the old cell's voltage curve. The new cell hits a voltage cliff under modem or display load before the gauge registers empty — the phone reads 25% but the cell voltage has already collapsed below the BMS cutoff threshold. One complete discharge cycle — draining to automatic shutdown, then charging fully — forces the coulomb counter to reset against the new cell's actual curve. After that cycle, the shutdowns stop.

Phone not powering on after the battery sat in storage

Lithium-polymer cells in storage self-discharge over weeks. If the cell drops below 2.5V, the BMS enters a lockout state and will not accept a normal charge request. Plug the phone into a wall adapter — not a PC USB port — and leave it for 20–30 minutes without pressing the power button. The charge IC will deliver a trickle current to bring the cell above the BMS wake threshold, typically 2.8V, at which point the phone will boot normally.