Navman N20 GPS Replacement Battery 3.7V 1230mAh

Navman N20 — 3.7V Li-Polymer Replacement Battery (BP/LP1230/11/A0001U)

This 3.7V, 1230mAh Li-Polymer cell replaces the original battery in the Navman N20 portable GPS navigator. It fits the N20 directly and restores the unit's ability to run on internal power during vehicle navigation. Capacity is rated at 4.55Wh, matching OEM specification.

• N20 platform fit: The N20 uses a flat Li-Polymer pouch cell with a three-contact connector tied to the onboard BMS. Voltage and connector pinout must match exactly — this cell meets both requirements, so the BMS handshake completes and the device boots normally.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the N20 platform. The BMS accepted the cell without fault codes, charging terminated correctly at 4.2V, and low-voltage cutoff triggered at the expected threshold.
• Cold-start satellite acquisition after swap: After fitting this cell, power the N20 fully on outdoors before driving. The unit performs a cold start after any full power interruption — first satellite fix takes 5–10 minutes. Subsequent warm starts drop well under a minute once the almanac is cached.

GPS accuracy reduced at low battery on the N20

When cell voltage drops below roughly 3.5V, some GPS units scale back receiver sensitivity to reduce current draw. On the N20, this shows up as position jumping or a widened accuracy circle on the map. The fix is straightforward — the receiver returns to full sensitivity once the battery is above 3.6V. If you see this regularly, the original cell has likely lost capacity and no longer holds charge near its rated level.

N20 shuts off without warning before the battery indicator hits empty

The N20's battery gauge reads from a fuel model calibrated to the original cell's discharge curve. A new or different cell may have a slightly different curve, so the device hits its voltage cutoff threshold before the on-screen indicator reaches zero. This is a calibration lag, not a fault. Run two or three full charge-to-cutoff cycles and the gauge will recalibrate to the new cell. After that, the warning should appear at the expected point — around 3.4–3.5V under load.