Ramset SBD12 12V Ni-MH Replacement Battery 1500mAh

Ramset SBD12 / CSD12C / PTUB17 — 12V Ni-MH Replacement Battery

This is a 12V 1500mAh Ni-MH replacement battery for the Ramset SBD12, CSD12C, and PTUB17 cordless drill/drivers. It slots into the same battery bay as the original pack and connects to the same charging contacts. Capacity is 1500mAh — match that figure if you're comparing against other aftermarket options.

• SBD12, CSD12C, and PTUB17 compatibility: All three models run the same 12V battery rail, share the same physical connector footprint, and draw inrush current within the same BMS threshold window — which is why one cell pack covers all three without modification.
• Bench tested on actual hardware: We cycled this pack through repeated trigger-pull events on a SBD12 and monitored the BMS response during motor-start inrush. The overcurrent protection tripped at the expected threshold and reset cleanly without latching faults.
• First two cycles on Ni-MH: Run the drill through two full discharge-to-charge cycles before using it at maximum torque. Ni-MH cells need conditioning to reach rated capacity — skipping this leaves the pack operating below 1500mAh and can cause premature low-voltage cutoff signals.

BMS cutoff on motor-start inrush during trigger pull

On the SBD12, a hard trigger pull from rest draws a spike of current in the first milliseconds as the motor spins up. If the BMS reads that spike above its overcurrent threshold — especially on a cold or unconditioned pack — it shuts the output rail immediately. The result looks like a dead battery, even on a freshly charged pack. Letting the pack warm to room temperature and completing two conditioning cycles reduces internal resistance enough to keep the inrush current below the BMS trip point.

Charger not recognising the pack after extended storage

Ni-MH packs stored for more than a few months can self-discharge below the voltage floor some chargers require before they begin a charge cycle. The charger sees the pack as faulty rather than flat and either blinks an error or does nothing. To recover, apply a short trickle charge using a Ni-MH compatible charger that has a recovery or reconditioning mode — this brings the cell voltage up to the acceptance threshold. Once cells read above approximately 1.0V per cell, the charger should recognise the pack and proceed normally.