Navigon 40 Easy GPS Compatible Battery 3.7V 1200mAh

Navigon 40 Easy / 40 Plus — 3.7V Li-Polymer Replacement Battery (8390-ZC01-0780)

This 3.7V 1200mAh Li-Polymer cell replaces the original battery in the Navigon 40 Easy and 40 Plus portable GPS navigators. It powers the display, processor, and GPS receiver module. Capacity matches the OEM spec at 1200mAh (4.44Wh).

• 40 Easy and 40 Plus compatibility: Both units share the same battery bay dimensions, connector pinout, and 3.7V supply rail. The BMS handshake is identical across the range, so one cell covers both models without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a Navigon 40 unit and confirmed the BMS accepted the cell without fault codes. Charge termination triggered cleanly at full voltage with no overcharge event.
• Cold-start after power interruption: After fitting this cell, power the GPS on outdoors before your first drive. The unit performs a cold satellite acquisition after any full power removal — allow 5 to 10 minutes to establish the first fix before relying on routing.

GPS accuracy reduced at low battery on the Navigon 40

The Navigon 40 series reduces power to the GPS receiver module when battery voltage drops below a certain threshold. This cuts the receiver's sensitivity, which means fewer satellites are tracked and position accuracy degrades. You may notice the blue location dot drifting or snapping to incorrect roads. Keep the unit charged above 3.6V during active navigation to avoid receiver throttling.

Device shuts off without warning before the low-battery indicator appears

This happens when the battery's actual capacity has drifted and the fuel gauge is no longer calibrated to the cell. The unit's voltage-threshold cutoff triggers before the on-screen indicator reaches the last bar. After fitting a new cell, run one full discharge cycle from 100% to automatic shutdown, then charge uninterrupted to 4.2V. That recalibrates the indicator to the new cell's curve.