Alpina AR 1 500 Replacement Battery 25.2V 3400mAh Li-Ion

Alpina AR 1 500 / AR2 1200 — 25.2V Li-ion Replacement Battery

This 25.2V, 3400mAh Li-ion battery replaces the original pack in the Alpina AR 1 500, AR1 500, AR2 600, and AR2 1200 cordless lawn mowers. It matches the original voltage rail and connector configuration the mower's BMS expects. Capacity is 3400mAh (85.68Wh) — taken from product data, not estimated.

• AR 1 500 and AR2 series compatibility: These models share the same 25.2V battery platform and connector footprint. The BMS handshake protocol is identical across the range, so one pack fits all listed variants without adapter or modification.
• Bench tested on actual hardware: We ran this pack through a full charge-discharge cycle on the AR 1 500 platform. The BMS held stable under simulated blade-motor inrush current and did not trip at normal residential cutting loads on dry grass.
• Seasonal storage tip: If the mower has sat through winter, bring the battery indoors overnight before the first spring cut. Below 10°C, Li-ion cells develop higher internal resistance. The blade motor's inrush current on a cold pack can trip the BMS before the blades reach full speed.

BMS cutoff under thick-grass or wet-grass blade load

The AR 1 500's blade motor draws significantly more current through dense or wet grass than on a clean dry lawn. If the instantaneous draw spikes past the BMS overcurrent threshold, the pack cuts power to protect the cells. This shows as the mower stopping abruptly mid-row. The fix is to slow the walking pace through heavy sections and let the blade maintain speed — this keeps draw below the trip point. If the mower cuts out, remove the pack, wait 30 seconds, and reinsert — the BMS resets once the thermal and current flags clear.

Charger shows fault light after mower sat all winter

Li-ion cells self-discharge during storage. If the pack sat unused for more than three months, cell voltage may have dropped below the charger's acceptance threshold — typically around 20V for a 25.2V pack. A fault light or no-charge response does not always mean the pack is dead. Place the battery in the charger and leave it for 15–20 minutes without interruption — many chargers run a recovery pulse at low current before switching to full charge. If the fault light persists after 20 minutes, check the charger terminals for corrosion and confirm the pack surface temperature is above 10°C before retrying.