Voxtel BMI071BD50 Compatible Battery 3.7V 1300mAh

Voxtel BMI071BD50 / BD50 — 3.7V Li-Polymer Replacement Battery (BALL-N911-DMED)

This is a 3.7V, 1300mAh lithium-polymer cell that replaces the original power source in the Voxtel BMI071BD50 and BD50 portable GPS navigators. It matches the OEM part number BALL-N911-DMED and restores full operating voltage to the navigation board. Capacity is 4.81Wh — identical to the original specification.

• BMI071BD50 and BD50 compatibility: Both models run from the same 3.7V single-cell lithium-polymer rail and use the same connector and BMS handshake profile, which is why they share this cell. Swapping to a mismatched voltage would prevent the navigation processor from booting correctly.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the GPS platform and confirmed the BMS reported state-of-charge accurately across the full voltage window, with no premature cutoff during active navigation loads.
• Cold-start behaviour after fitting: After installing this battery, take the unit outdoors and power it on before driving. A full power interruption forces a cold start — the GPS receiver needs to reacquire satellite almanac data from scratch, which typically takes 5–10 minutes for the first fix. Subsequent starts will be faster once the almanac is cached.

GPS accuracy reduced at low battery on the BMI071BD50

As cell voltage drops toward the lower end of the 3.7V nominal range, some GPS units reduce RF receiver sensitivity to conserve power. On the BMI071BD50, this can manifest as position drift or a weaker satellite signal count before the battery indicator shows critical. The device is not malfunctioning — it is shedding power from the receiver first. Keeping the cell charged above 3.6V maintains full receiver sensitivity.

Device shuts off without low-battery warning on the BD50

After a full battery swap, the fuel-gauge circuit in the BD50 has no prior discharge history to reference, so its voltage-to-capacity calibration is uncalibrated on the first cycle. The unit can hit the hardware cutoff voltage before the on-screen warning triggers. Run one full charge-to-discharge cycle under normal navigation use and the indicator will track accurately from the second cycle onward. The hardware cutoff threshold is approximately 3.0V.