About this replacement
Navigon 81xx Series — 3.7V Li-Polymer Replacement Battery (761NH50371W)
This 3.7V, 1300mAh lithium-polymer cell replaces the original battery in the Navigon 8110 and 8310 GPS navigators. It matches the OEM part number 761NH50371W and fits the slim 64.10 × 42.60 × 4.80mm cavity of the 81xx chassis. Capacity is 4.81Wh — identical to factory spec.
- 8110 and 8310 compatibility: Both models run the same voltage rail and share the 761NH50371W connector footprint. The BMS on each unit handshakes at 3.7V nominal — no firmware difference between them affects how the replacement cell is recognised at power-on.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the 81xx platform. The BMS accepted the cell without fault codes, held the low-voltage cutoff at the correct threshold, and showed no thermal anomalies during fast-charge phases.
- First-fix cold start after swap: After fitting this cell, power the unit on outdoors and let it acquire a satellite fix before driving. GPS performs a full cold start after any complete power interruption — first fix typically takes 5–10 minutes. Subsequent warm starts drop back under a minute once almanac data is cached.
GPS accuracy reduced at low battery on the 81xx
The Navigon 81xx lowers receiver sensitivity when battery voltage drops near the cutoff threshold. This saves power but weakens signal acquisition, especially in urban canyons or under tree cover. The symptom is position drift or a "searching for GPS" banner that appears well before the battery indicator reads empty. Keeping the cell above 3.5V under load prevents the unit from triggering this power-save mode.
Navigon 81xx shuts off without warning before the battery bar empties
After a battery swap, the fuel-gauge calibration stored on the device no longer matches the new cell's actual discharge curve. The unit reads remaining charge against the old degraded baseline, so the low-battery warning fires late — or not at all — before hard cutoff. The fix is a full discharge-to-shutdown followed by a complete charge to 4.2V with the unit off. One full cycle re-anchors the gauge to the replacement cell's real capacity.