About this replacement
Acer AO532h Series — 10.8V Li-ion Replacement Battery (UM09C31)
This 10.8V, 6600mAh Li-ion battery replaces the original cell in the Acer Aspire One 532h netbook range. It fits the AO532h-2Db, AO532h-2Dr, AO532h-2Ds, AO532h-21b, and over 45 additional 532h variants. OEM part numbers covered include UM09C31, UM09G31, UM09G41, UM09H31, UM09H36, UM09H41, UM09H56, UM09H70, UM09H73, UM09H75, and UM09G51.
- 532h series compatibility: All AO532h variants share the same 10.8V rail, three-pin connector, and BMS handshake protocol. The same cell fits across the range without hardware modification.
- Bench tested on actual hardware: We ran this cell on an AO532h unit and confirmed the BMS initialised correctly, accepted a full charge cycle, and passed the voltage floor check at 9.0V cutoff without triggering a protection trip.
- First-cycle calibration on the 532h: After installing, let the battery discharge fully to hibernate cutoff, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap on this netbook line.
Why the AO532h BIOS reports poor battery health after a cell swap
The 532h stores battery health data in the EEPROM of the original cell, not in the motherboard firmware. When a new cell installs, the BIOS reads zero charge cycles and a mismatched Wh rating — it flags this as a fault. Running one full discharge-to-hibernate and uninterrupted recharge gives the fuel gauge IC enough data to overwrite the stale EEPROM values. After two to three full cycles, the health indicator returns to normal.
AO532h shutting down at 20–30% battery remaining
This happens when the cell voltage drops sharply under combined CPU and display load — a voltage cliff the fuel gauge IC did not anticipate. The OS reads a safe percentage, but the actual cell voltage collapses below the 9.0V BMS cutoff before the gauge catches up. Running two full calibration cycles lets the fuel gauge IC map the new cell's discharge curve accurately. After calibration, the shutdown threshold shifts back to the correct low-battery warning point near 5–8%.