About this replacement
Lenovo A2107 / A2207 Series — 3.7V Li-Polymer Replacement Battery (BL195 / L12T1P31)
This is a 3.7V, 3200mAh (11.84Wh) lithium-polymer replacement battery for the Lenovo A2107, A2207, A2, and R6907 tablets. It replaces OEM parts BL195 and L12T1P31. Fit this when the original cell no longer holds a usable charge or fails to power the tablet through normal use.
- A2107 and A2207 compatibility: Both tablets share the same 3.7V battery architecture, connector pinout, and BMS handshake protocol — the same cell works across the A2107, A2207, A2, and R6907 without modification.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on A2107 hardware. The BMS accepted the cell without fault codes, voltage held steady under combined display and Wi-Fi load, and the charge IC completed a full cycle without thermal cutoff.
- Fuel gauge recalibration after swap: After fitting this battery, run the tablet down to automatic shutoff, then charge it uninterrupted to 100% in one session. This forces the fuel gauge IC to map its calibration thresholds against the new cell and clears the inaccurate percentage readings that commonly appear straight after a replacement.
Tablet shutting down at 15–25% remaining after battery swap
The A2107's fuel gauge IC stores calibration data from the original cell. When a new cell goes in, the IC still uses the old discharge curve to predict cutoff voltage. Under combined display brightness and Wi-Fi load, actual cell voltage drops faster than the IC expects — the tablet hits the hardware low-voltage cutoff before the percentage reaches zero. One full discharge-to-shutoff cycle followed by an uninterrupted charge to 100% resets the stored curve. After that cycle, shutdowns at 15–25% typically stop.
A2107 showing a frozen or jumping battery percentage after replacement
A percentage that sticks at one value for long periods, then jumps suddenly, points to fuel gauge drift — the IC is interpolating from stale data calibrated to the worn-out original cell. The new cell's actual state of charge and the reported figure diverge because the reference points no longer match. Run one complete cycle: discharge to automatic shutoff, then charge without interruption to 100%. The fuel gauge re-anchors its 0% and 100% reference points against the new cell's actual voltage range, and the display stabilises.