Lizard M4 Lawn Mower Replacement Battery 25.9V 10200mAh

Lizard M4 / M440 / M480 Series — 25.9V Li-ion Replacement Battery (110Z03700A)

This is a 25.9V, 10200mAh Li-ion battery that replaces the original 110Z03700A pack used in Lizard cordless lawn mowers. It fits the M4, M440, M480, and M485 platforms, along with five additional models in the same series. The voltage rail and connector match the OEM spec exactly.

• M4 / M440 / M480 / M485 platform fit: These models share the same 25.9V battery architecture, connector pinout, and BMS handshake protocol — so one cell pack covers the full range without adapters or firmware workarounds.
• Bench tested on actual hardware: We cycled this pack through sustained blade-motor load draws and confirmed the BMS holds stable through repeated high-inrush start events without nuisance tripping under normal cutting conditions.
• Seasonal storage tip: If the mower has sat unused for more than three months, charge the pack to 100% before the first cut — a partially depleted cell left in a cold garage can drop below the BMS acceptance threshold, which the charger will flag as a fault rather than a dead cell.

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

The blade motor on the M4 series draws a sharp inrush current every time it bites into dense or wet grass — sometimes two to three times the steady-state draw. If the pack voltage sags too fast during that spike, the BMS reads it as an overcurrent event and shuts the output down. This is a protection trigger, not a cell failure. Letting the mower slow down slightly before hitting a dense patch keeps the inrush within the BMS window and stops nuisance cutoffs.

Charger showing a fault light after the mower sat all winter

Li-ion cells self-discharge slowly during storage — a pack left in a cold garage from October to April can fall below 20V, which is under the 21V floor most Lizard chargers use to begin a charge cycle. The charger sees that voltage and refuses to engage, flagging it as a fault. This is a voltage-floor protection, not a sign the pack is dead. To recover a deeply discharged pack, some users have had success with a brief boost charge from a bench power supply set to 25.2V at 0.5A until the pack rises above 21V, at which point the standard charger will take over normally.