About this replacement
HILTI SFL 24 / TE 2-A Series — 24V Ni-MH Replacement Battery (24V B24)
This is a 24V, 2000mAh Ni-MH replacement battery for the HILTI SFL 24 cordless work light and its platform siblings. It also fits the TE 2-A, UH 240-A, and WSC 55-A24 — all 24V Ni-MH tools sharing the same pack architecture. Capacity is 2000mAh (48Wh) as specified against OEM part numbers 24V B24, B 24/2.0, and B 24/3.0.
- Cross-platform 24V compatibility: The SFL 24, TE 2-A, UH 240-A, and WSC 55-A24 all run off the same 24V Ni-MH rail with a shared connector and BMS handshake protocol. One pack services all four tools without modification.
- Bench tested on actual hardware: We cycled this pack on the SFL 24 through charge and discharge at rated current. The BMS held cutoff at the correct low-voltage threshold and did not trigger a false overcurrent fault during the flashlight's inrush at switch-on.
- Ni-MH conditioning on the WSC 55-A24 and TE 2-A: Ni-MH cells in high-draw rotary tools develop memory effect faster than in lighting applications. Run two full discharge-to-cutoff cycles on first use in the TE 2-A or WSC 55-A24 before returning to partial-discharge use — this sets the BMS capacity baseline accurately.
Charger blinking red on this 24V Ni-MH pack after storage
Ni-MH packs self-discharge during storage and can drop below the HILTI charger's acceptance voltage threshold — typically around 18–20V on a 24V pack. When the charger sees voltage below that floor, it reads the pack as faulty and throws a red blink instead of starting a charge cycle. The fix is a slow "trickle prime": some HILTI chargers have a recovery or conditioning mode; if yours does not, a compatible Ni-MH charger with a manual recovery setting can bring the pack back above the acceptance threshold. Once cell voltage climbs above 20V, place it back in the HILTI charger and the green charge cycle should start normally.
WSC 55-A24 bogs and loses torque mid-cut
Mid-cut bogging on the WSC 55-A24 is almost always voltage sag — the pack's internal resistance climbs under sustained saw load, and the voltage rail drops enough to reduce motor torque. On a Ni-MH pack, this worsens if the cells have been repeatedly shallow-cycled without a full discharge. Check the rail contacts on both the pack and the tool for oxidation or carbon build-up first, then run a full discharge-to-cutoff cycle. If sag persists under load, measure open-circuit voltage immediately after a full charge — it should read at or above 24V; a reading below 22V under no load indicates cell degradation.