About this replacement
Olight Baton 3 / Perun Mini / S1R Baton II — 3.7V Li-ion Replacement Battery (IMR16340)
This is a 3.7V 680mAh (2.52Wh) Li-ion IMR16340 cell for the Olight Baton 3, Perun Mini, and S1R Baton II flashlights. All three lights use the same 16340 format cell and share identical voltage and connector requirements. Capacity figure comes from the product specification — 680mAh.
- Baton 3, Perun Mini, S1R Baton II compatibility: These three lights share the same 16340 cell format, 3.7V nominal voltage rail, and magnetic-charge contact plate. The BMS in each model targets the same charge termination voltage, so one cell specification covers all three without modification.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the Baton 3 driver board. The BMS accepted the cell cleanly, charged via the magnetic port without fault, and stepped down output correctly as voltage dropped toward the low-voltage cutoff threshold.
- Single-cell replacement protocol: The Baton 3, Perun Mini, and S1R Baton II each run a single cell — so there is no multi-cell balance issue. However, do not mix this new cell with a partially discharged original in repeated hot-swap cycling. Swap fully when output noticeably drops from a known full charge.
Why the Baton 3 steps down output before the indicator signals low battery
The Baton 3 driver runs a brownout protection circuit that cuts output current before the cell voltage actually hits the hard low-voltage cutoff. This is intentional — the driver reads a voltage sag under load and steps down to protect the cell from deep discharge. You will see the light drop from turbo or high to a lower mode while the indicator still shows charge remaining. It is not a fault with the cell. The driver is reading instantaneous load voltage, not resting voltage.
Turbo mode draining the cell noticeably faster than standard or medium
Turbo mode on the Baton 3 draws significantly more current than standard or medium modes — often five to ten times the draw. A 680mAh cell handles that current, but the relationship between capacity and runtime is not linear at high draw rates. The cell's internal resistance causes a greater voltage drop under turbo current, which triggers the driver's step-down protection sooner. To extend usable time per charge, switch to high or medium for sustained use and reserve turbo for short bursts.