About this replacement
Yard Force Amiro 350 Series — 18V Li-ion Replacement Battery (GMBE-SP10283)
This is an 18V Li-ion replacement battery rated at 2500mAh (45Wh) for the Yard Force Amiro 350 robotic lawn mower. It fits the Amiro 350, 350i, 400, and 400i models. The OEM part numbers covered are GMBE-SP10283, GMBE-SP11571, and 1920726.
- Amiro 350 / 350i / 400 / 400i compatibility: These models share the same 18V battery platform, connector pinout, and BMS handshake protocol. One battery fits the full range without modification.
- Bench tested on actual hardware: We ran this battery through charge and discharge cycles on the Amiro platform. The BMS balanced cells correctly and tripped protection at the expected voltage floor without false cutoffs under simulated blade-motor load.
- Seasonal storage care: If the mower has sat unused over winter, bring the battery indoors overnight before the first spring charge. Li-ion cells discharged below 10°C have higher internal resistance — the blade motor's inrush current can trip the BMS on a cold pack before the mower cuts a single row.
BMS cutoff on thick-grass or wet-grass blade load
The Amiro's blade motor pulls significantly more current through dense or wet grass than on a dry, short lawn. If the pack voltage dips sharply during that inrush, the BMS interprets it as an undervoltage event and cuts output to protect the cells. This is more likely with a new battery in its first few cycles before the cells have reached full capacity. If it happens repeatedly, check that the mower's cutting height is set correctly for the current grass length — reducing load per pass keeps current draw within the BMS threshold.
Charger refusing to accept the pack after winter storage
Li-ion cells that self-discharge below roughly 2.5V per cell over a long storage period will be rejected by standard chargers as a safety measure. The Amiro charger shows a fault light rather than beginning a charge cycle. To recover the pack, place it in a warm room (above 15°C) for two hours, then reconnect the charger — some chargers include a trickle-recovery mode that kicks in once the pack is at ambient temperature. If the charger still shows a fault after that, the cells have dropped below the recovery threshold and the battery needs replacing.