About this replacement
Acer Iconia Tab 10 A3-A20 — 3.8V Li-Polymer Replacement Battery (AP14A8M)
This is a 3.8V, 5900mAh Li-Polymer replacement battery for the Acer Iconia Tab 10 A3-A20 and A3-A20FHD 10-inch Android tablets. It also fits the SW5-011 and SW5-012 models. OEM part numbers AP14A8M, KT.0020G.004, and AP14A4M all cross to this cell.
- A3-A20 and SW5 series fit: The A3-A20, A3-A20FHD, SW5-011, and SW5-012 share the same 3.8V Li-Polymer cell format, connector pinout, and BMS communication protocol — one battery covers all four variants without modification.
- Bench tested on actual hardware: We cycled this battery through charge and discharge on the A3-A20 platform. The BMS handshake completed without fault codes, charge acceptance was clean from 0% to 100%, and cell voltage held within spec under combined display and Wi-Fi load.
- Fuel gauge reset after installation: After fitting this battery, run one full discharge to automatic shutoff, then charge uninterrupted to 100%. This resets the fuel gauge IC calibration against the new cell and clears the inaccurate percentage readings that appear immediately after a swap.
Tablet shutting down at 15–25% remaining after battery replacement
The A3-A20 draws hard on the battery when the display is at full brightness and Wi-Fi is active simultaneously. If the fuel gauge IC is still calibrated to the old degraded cell, it misreads the new cell's voltage curve and triggers a low-voltage shutdown well before actual depletion. This is not a faulty battery — it is a calibration mismatch. Run one full discharge to automatic shutoff followed by an uninterrupted charge to 100%, and the shutdowns stop.
Fast charging unavailable after fitting a new battery
The A3-A20's charge IC negotiates charging rate over the first accepted charge cycle after a new cell is installed. Until that cycle completes, the tablet may default to standard 5V charging and ignore USB-PD input. This is normal behaviour — it is not a charger fault or a compatibility issue. Complete one full charge from near-zero to 100% using the original Acer charger, and fast charge negotiation re-enables at the start of the next session.