About this replacement
HTC One Mini 2 / One M8 Mini — 3.8V Li-Polymer Replacement Battery (BOP6M100)
This is a 3.8V, 2100mAh lithium-polymer cell that replaces the original BOP6M100 battery in the HTC One Mini 2, M5, One M8 Mini, and 0P6B640. It fits the same physical footprint at 77.92 × 54.41 × 3.06mm and connects to the same flex ribbon contact. Swap it when the original cell no longer holds enough charge to get through a normal day of use.
- One Mini 2 and M8 Mini platform fit: Both models share the same battery bay dimensions, connector pitch, and BMS handshake protocol — which is why a single cell covers the full list. The fuel gauge IC on both boards reads the same cell chemistry signature, so the percentage readout initialises correctly after one full cycle.
- Bench tested on actual hardware: We ran this cell through charge and discharge on the One Mini 2 board. The BMS accepted the cell without error flags, charge termination triggered correctly at 4.35V, and the protection circuit tripped as expected on a simulated over-discharge event.
- Fuel gauge recalibration on first use: After installation, run one complete discharge-to-charge cycle with fast charging disabled. The coulomb counter on the HTC fuel gauge IC needs a full uninterrupted cycle to map the new cell's discharge curve — skipping this step is why new cells often read erratic percentages on the first day.
Sudden shutdown at 20–30% on the One Mini 2
This happens when the cell can no longer sustain voltage under the combined load of the modem, display, and processor. As the cell ages, its internal resistance rises — voltage drops sharply under load even when the coulomb counter still shows charge remaining. The phone's low-voltage cutoff triggers before the percentage reaches zero. A new cell with lower internal resistance eliminates the voltage cliff, but the fuel gauge IC still needs one full calibration cycle to report percentages accurately after the swap.
Phone not powering on after the replacement cell sat in storage
Li-polymer cells self-discharge during storage. If the cell voltage drops below approximately 2.5V, the BMS enters lockout mode to prevent damage and the phone will not respond to a power button press. Plug in a known-good charger and leave it connected for 15–20 minutes without pressing anything — the charge IC needs time to trickle current into the cell and bring it above the BMS re-enable threshold of around 3.0V. Once the phone shows a charge indicator on screen, normal charging resumes automatically.