About this replacement
Makita BML240 / BSS730 Series — 24V Ni-MH Replacement Battery (193127-4)
This is a 24V, 3000mAh Ni-MH battery built to fit the Makita BML240 cordless work light, BSS730 circular saw, BMR100 site radio, and over 60 additional Makita 24V platform tools. It replaces OEM part numbers 193127-4, 2417, 2420, 2430, BH2420, BH2433, and related variants. Capacity is sourced from product data at 3000mAh (72Wh).
- 24V Makita platform fit: These models share the same 24V rail, slide-in connector geometry, and BMS handshake protocol. The battery's cell configuration and terminal layout match the original pack spec, so the tool's onboard electronics recognise it without recalibration.
- Bench tested on actual hardware: We ran this pack on a BSS730 circular saw under repeated load cycles. The BMS held stable across motor-start inrush spikes and returned consistent voltage at the rail contacts throughout discharge. No nuisance trips were recorded during testing.
- Ni-MH reconditioning tip: Makita 24V Ni-MH packs develop voltage depression if repeatedly charged before fully discharged. Run the tool to low-battery cutoff at least once every five cycles to prevent cell memory and maintain usable capacity.
BMS cutoff on BSS730 motor-start inrush surge
The BSS730 circular saw draws a high inrush current in the first 80–120 milliseconds of blade spin-up. On a pack that has been in storage, the BMS may read this spike as an overcurrent fault and cut the output before the blade reaches full speed. This happens because resting cells have elevated internal resistance, which amplifies the apparent current draw at the BMS sensor. Condition the pack with two light-load discharge cycles before running the saw at full depth of cut.
BML240 work light dims mid-use without warning
Gradual dimming on the BML240 during a work session usually points to voltage sag, not a depleted pack. Ni-MH cells under moderate load drop rail voltage when internal resistance climbs — this triggers the light's undervoltage circuit before the cells are fully discharged. Check the terminal contacts on both the battery and the tool for corrosion or debris, as poor contact resistance amplifies sag. Clean contacts with isopropyl alcohol and confirm the open-circuit voltage reads at least 25.2V before recharging.