About this replacement
Navigon 70 Easy / 70 Plus / 70 Premium — 3.7V Li-Polymer Replacement Battery (Topaz / TOPAZPCZF1045003501)
This 3.7V, 1200mAh lithium-polymer cell replaces the original battery in the Navigon 70 Easy, 70 Plus, and 70 Premium portable GPS navigators. It fits the internal battery slot directly and connects to the device's power management circuit at the correct voltage rail. Dimensions are 60.24 × 36.53 × 4.92mm — measure your existing cell before fitting if you are unsure.
- 70 Easy, 70 Plus, and 70 Premium compatibility: All three models share the same internal battery bay dimensions, connector orientation, and 3.7V power rail. The same cell serves all three without modification.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on a GPS navigation unit, confirming the protection circuit trips correctly at undervoltage and that the cell accepts a full charge without thermal anomaly.
- Cold-start behaviour after fitting: After installing this cell, take the device outdoors and power it on before driving. GPS units perform a cold start after any full power interruption — first satellite acquisition can take 5–10 minutes. Subsequent locks come in under a minute once ephemeris data is stored.
GPS accuracy dropping when the battery charge is low
The Navigon 70 series reduces power draw to the GPS receiver module when battery voltage sags below a threshold. This shows up as slower position updates, increased drift on the map, or the blue dot jumping between streets. It is not a software glitch — the receiver is running at reduced sensitivity to stay within the available power budget. Keeping the cell charged above 3.5V during active navigation prevents the receiver from entering this reduced-power state.
Device shuts off without warning despite the battery indicator showing charge remaining
The on-screen battery indicator in the Navigon 70 series is calibrated to the original cell's discharge curve. A new cell — or any cell with different internal resistance — will read inaccurately until the device completes two or three full charge and discharge cycles. During this calibration period, the device hits its undervoltage cutoff threshold at 3.2V while the indicator still shows one or two bars. Run two full cycles and the indicator will track the actual charge state correctly.