About this replacement
Navman Otanium 100 — 3.7V Li-ion Replacement Battery (800-332-2436)
This is a 3.7V 5600mAh Li-ion replacement battery for the Navman Otanium 100 portable GPS navigator. It matches OEM part number 800-332-2436 and fits directly into the Otanium 100 housing. Capacity is rated at 20.72Wh from the factory spec.
- Otanium 100 fit: The Otanium 100 runs on a single-cell 3.7V Li-ion pack with a specific connector and physical envelope — 209.10 × 34.40 × 34.40mm. This cell matches those dimensions and the battery management handshake the unit expects on power-up.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the Otanium 100 platform and confirmed the BMS reported full charge correctly, with no false low-battery flags at any point in the discharge curve.
- Cold-start acquisition after fitting: After fitting this cell, power the unit on outdoors and let it run until it acquires a satellite fix before driving. The GPS performs a full cold start after any complete power interruption — first fix after a swap typically takes 5–10 minutes. Subsequent warm starts are under a minute.
GPS accuracy reducing at low charge on the Otanium 100
As battery voltage drops toward the lower end of the discharge curve, some GPS units step down receiver sensitivity to conserve power. On the Otanium 100, this can show up as slower position updates or increased positional drift during active navigation. The GPS receiver is one of the highest-draw components in the unit — it competes with the backlit display for whatever charge remains. Keeping the battery above 3.5V under load is the practical threshold where receiver performance stays consistent.
Otanium 100 shutting off without warning before the low-battery indicator appears
This happens when the device's low-battery indicator threshold is not calibrated to the actual voltage curve of the new cell. The unit cuts off at the hardware protection floor before the software warning triggers visually. Running one full charge-to-cutoff cycle recalibrates the threshold. After that cycle, the low-battery warning should appear at least a few minutes before shutdown at 3.4–3.5V.