Ledlenser P5R Torch Replacement Battery 3.7V 800mAh Li-ion

Ledlenser Torche P5R / P5R.2 — 3.7V Li-ion Replacement Battery (7703)

This is a 3.7V, 800mAh Li-ion battery for the Ledlenser Torche P5R and P5R.2 rechargeable flashlights. It replaces OEM part number 7703 and fits the original battery compartment without modification. The P5R uses a single cylindrical cell with an integrated contact arrangement that this battery matches exactly.

• P5R and P5R.2 compatibility: Both models share the same battery housing dimensions and the same contact orientation, so this 52.00 × 14.50 × 14.30mm cell fits either variant without adapters or wiring changes.
• Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on the P5R driver. The protection circuit cut off cleanly at the low-voltage threshold, and the charging circuit accepted the cell without error flags.
• Turbo mode draw tip: The P5R's turbo output pulls significantly higher current than its standard modes. Keep contacts clean on both the cell and the torch head — any resistance at the contact point causes a voltage drop the driver interprets as a depleted cell, stepping output down prematurely.

Flashlight driver stepping down output before battery indicator shows low

The P5R driver monitors cell voltage in real time and reduces output once voltage sags under load — even if the indicator hasn't triggered yet. On turbo, this can happen well before the cell is fully discharged because turbo draws enough current to drag the terminal voltage below the driver's threshold momentarily. This is brownout protection, not a faulty battery. Switching to the mid or low output mode stops the sag and lets the remaining charge deliver consistent light output.

P5R cycling through modes on its own near end of charge

When the cell voltage drops to around 3.2–3.3V under load, the driver can lose enough voltage headroom to briefly reset, causing the light to step through modes or flicker. This is the driver's low-voltage cutoff cycling rather than a defective cell. A fresh cell eliminates this — but if it appears early in the cell's life, check that the tail cap is fully tightened, as a loose connection creates resistance that mimics a flat battery. Tighten the cap and retest before concluding the cell is at fault.