About this replacement
SCANGRIP Slim — 3.7V Li-ion Replacement Battery (03.5388)
This is a 3.7V, 2600mAh (9.62Wh) Li-ion replacement battery for the SCANGRIP Slim work light (03.5612). It replaces OEM part 03.5388 when the original cell degrades and can no longer hold a usable charge. Swap it in and the Slim returns to full output levels.
- Slim platform fit: The 03.5612 Slim uses a single 18650-format Li-ion cell at 3.7V nominal. The driver circuit and BMS handshake are tuned to that voltage rail — substituting a different chemistry or voltage causes the driver to misread state-of-charge and step down output prematurely.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the Slim platform. The BMS accepted the cell without fault flags, protection cutoffs triggered correctly at low-voltage threshold, and the driver held full output until the expected depletion point.
- Turbo mode draw: The Slim's turbo mode pulls significantly more current than standard mode from a single cell. Keep the cell contacts clean — oxidation on a single-cell light has an outsized effect on voltage sag under high-current draw, causing the driver to step down output even with remaining capacity.
Why the SCANGRIP Slim dims before the battery indicator shows low
The Slim's driver runs brownout protection that steps down output before the cell hits its hard cutoff voltage. This protects the cell from deep discharge but means the light visibly dims while the indicator still shows charge remaining. It is not a faulty cell — it is the driver throttling current draw to keep the cell above approximately 3.0V. If you see this earlier than expected, check that the cell contacts are clean and making solid connection.
New battery fitted but Slim still shows weak output from the start
A new cell that has been stored for an extended period can arrive at a low state of charge — sometimes below 3.4V — which puts it within the driver's reduced-output window immediately. The Slim driver reads cell voltage directly and throttles output when voltage is low, regardless of whether the cell is new or old. Charge the replacement fully before first use and confirm the charger reaches the 4.2V termination point. If the charger indicator never flips to complete, the charger contacts or the cell itself should be checked.