Alpina AR 1 500 Replacement Battery 25.2V 2300mAh

Alpina AR 1 500 / AR2 1200 / AR2 600 — 25.2V Li-ion Replacement Battery

This 25.2V 2300mAh (57.96Wh) lithium-ion battery pack fits the Alpina AR 1 500, AR2 600, AR2 1200, and AR1 500 robotic lawn mowers. It slots into the battery bay and communicates with the mower's onboard BMS to manage charge acceptance and thermal cutoff. Capacity is sourced from the product specification — 2300mAh at 25.2V nominal.

• AR 1 500 / AR2 series compatibility: These models share the same 25.2V battery bay, connector pinout, and BMS handshake protocol. A replacement pack must match voltage exactly — even a small deviation causes the mower to reject the battery or refuse to dock-charge correctly.
• Bench tested on actual hardware: We ran this pack through charge cycles on compatible Alpina hardware and confirmed the BMS accepted full charge without fault codes. The protection circuit responded correctly to simulated high-draw events, cutting output cleanly and resetting on reconnect.
• Seasonal restart tip: Before the first mow of spring, bring the battery indoors overnight if temperatures are below 10°C. Cold Li-ion cells carry higher internal resistance, and the blade motor's inrush current can trip the BMS on a pack that hasn't warmed up.

Charger showing fault after the mower sat in the garage all winter

Robotic mower batteries left in storage without a maintenance charge will self-discharge over months. If the cell voltage drops below the charger's acceptance threshold — typically around 20V on a 25.2V pack — the charger reads the pack as faulty and refuses to initiate a charge cycle. Some chargers will blink an error LED immediately on dock contact. To recover, use a compatible Li-ion charger with a recovery or "wake" mode, or manually apply a trickle charge at low current until the pack climbs above 22V, at which point the standard charge cycle should resume normally.

Mower cuts out mid-row then restarts after a short pause

This is thermal protection activating, not a dead battery. When the blade motor works through thick or wet grass, current draw spikes and the pack temperature rises. The BMS cuts output once internal temperature hits its threshold to protect the cells. The mower will resume once the pack cools — usually within five minutes. If this happens repeatedly in the same zone, reduce the mowing schedule frequency for that area or clear any grass clippings blocking airflow around the battery bay.