About this replacement
Navman S30 / S50 / S70 / S80 Series — 3.7V Li-ion Replacement Battery (BP-LP850/11-A1 L)
This is a 3.7V 1250mAh lithium-ion battery for the Navman S30, S50, S70, and S80 portable GPS navigators. It replaces OEM part BP-LP850/11-A1 L. Swap it in when the original cell no longer holds a charge or causes unexpected shutdowns mid-route.
- S-series model compatibility: The S30, S50, S70, and S80 share the same 3.7V single-cell architecture, identical connector pinout, and the same physical battery bay dimensions — so one cell fits all four models without any modification.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the S-series platform. The BMS accepted a full charge without error flags, and the device voltage curve stayed within the expected 3.0V cutoff to 4.2V ceiling throughout.
- Cold-start satellite acquisition after fitting: After fitting a new cell, take the unit outdoors and power it on before driving. A full power interruption clears the GPS receiver's satellite almanac, so the first fix after a swap takes 5–10 minutes. Subsequent power cycles warm-start and lock much faster.
GPS accuracy reduced when battery level drops below 30%
Some Navman S-series units scale back GPS receiver sensitivity at low battery to protect the cell from deep discharge. The unit stays on, but satellite signal strength drops and position updates can become less frequent. This isn't a faulty battery or antenna — it's the device managing draw. Keep the unit charged above 30% during active navigation to maintain full receiver output.
Device shuts off without a low-battery warning
After a battery swap, the S-series fuel gauge is uncalibrated to the new cell. The on-screen battery indicator can still show two or three bars when the cell voltage is already near the 3.0V cutoff threshold. The device then cuts power without the usual warning. Run two or three full charge and discharge cycles to let the fuel gauge re-calibrate to the new cell's actual capacity curve.