About this replacement
Husqvarna Automower 265ACX Series — 22V Li-ion Replacement Battery (578 84 87-02)
This 22V 5200mAh (114.4Wh) Li-ion battery fits the Husqvarna Automower 265ACX, 265ACX G2-2, and the 2012 and 2014 production variants. It replaces the original pack when cell capacity has dropped enough to shorten cutting runs or cause mid-cycle shutdowns. Voltage, connector, and BMS communication match the docking station's charge handshake on all covered models.
- 265ACX platform compatibility: The 265ACX and its production year variants share the same 22V rail, physical housing dimensions, and BMS data lines. This battery slots into all of them without modification because the connector pinout and charge protocol did not change across those revisions.
- Bench tested on actual hardware: We ran this pack through the docking station charge cycle and verified BMS handshake, cell balance at full charge, and discharge behaviour under simulated blade-motor inrush load. The BMS held the 22V rail without tripping during the high-draw start pulse.
- Seasonal storage tip for Automower packs: Before parking the mower for winter, run it to roughly 50% charge — not flat — then remove the battery and store it indoors. A fully discharged Li-ion pack left at low temperature over several months can drop below the BMS acceptance threshold, and the docking station will refuse to charge it in spring.
BMS cutoff on thick-grass and wet-grass blade load
The 265ACX blade motor draws a short inrush spike every time it bites into dense or wet grass. If the battery's cells are aged or cold, internal resistance climbs and the BMS interprets that voltage sag as an overload event, cutting power to protect the cells. A new pack at room temperature handles this inrush without tripping because internal resistance is lower and the cells recover voltage quickly after the spike. If cutouts persist even with a fresh battery, check whether the mowing schedule is pushing the mower into the same dense-growth zone repeatedly — spreading passes reduces consecutive load events.
Docking station showing fault light after the mower sat all winter
Li-ion cells self-discharge slowly over months, and a pack left in an unheated garage from autumn to spring can fall below the minimum voltage the docking station accepts — typically around 14–16V for a 22V pack, depending on the charger's acceptance window. The station sees a voltage too low to confirm a healthy pack and throws a fault rather than risk charging a potentially damaged cell. To recover a pack that has discharged into this range, some chargers have a recovery or reconditioning mode; if yours does not, the pack may need replacement. Prevent this by storing the battery at roughly 50% charge indoors.