About this replacement
LawnMaster 20VMWGT Series — 24V Li-ion Replacement Battery (24LB1304)
This is a 24V 1300mAh Li-ion replacement battery for the LawnMaster 20VMWGT cordless lawn mower and compatible models including the 24VMWBL, CLGT2412S, and CLM2413A. It replaces OEM part numbers 24LB1304, 24LB4005, and 541286. Voltage and connector match the original pack exactly.
- Cross-model fit on 20VMWGT and CLGT2412S platforms: These models share the same 24V battery rail, connector housing, and BMS handshake protocol — which is why one pack covers the full lineup. Swapping a pack from a 24VMWBL into a CLGT2412S works without modification because the cell group voltage and terminal orientation are identical across the series.
- Bench tested on actual hardware: We ran this pack through full charge and discharge cycles on the 20VMWGT platform. The BMS responded correctly to motor inrush at blade start, held voltage under continuous cut load, and tripped thermal protection at the expected threshold without nuisance cutoffs on normal turf.
- Seasonal storage care: Before the first cut of the season, 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 on a cold pack can trip the BMS before the mower even starts cutting.
BMS cutoff on thick-grass and wet-grass blade load
The 20VMWGT blade motor draws significantly more current through dense or wet grass than on dry, even turf. When that inrush spike exceeds the BMS current threshold — typically on a standing-start cut into long wet growth — the pack shuts down as a protection response, not a fault. Let the mower sit for five minutes before restarting; the BMS resets once cell temperature drops back within range. To reduce trip frequency, lower the cutting height in two passes rather than one on heavy growth.
Charger showing fault light after mower sat unused all winter
Li-ion packs left in storage without a charge top-up will self-discharge below the charger's acceptance voltage threshold — often under 18V on a 24V pack after several months. When that happens, the charger reads the pack as faulty and refuses to begin the charge cycle. Some OEM chargers can recover a deeply discharged pack if you hold the charge button for 10–15 seconds on insertion; this forces a pre-charge pulse that raises cell voltage back above the acceptance floor. If the fault light clears within two minutes and normal charging begins, the cells are recovering — if it stays on past five minutes, cell damage from deep discharge is likely.