Navilock BT-315 Replacement Battery 3.7V 1800mAh

Navilock BT-315 — 3.7V Li-ion Replacement Battery

This 3.7V, 1800mAh (6.66Wh) lithium-ion cell replaces the original battery in the Navilock BT-315 portable GPS navigator. It restores power to the unit when the original cell has degraded to the point where the device no longer holds a usable charge. Dimensions are 52.98 × 35.39 × 11.61mm — measure your existing cell before fitting.

• BT-315 platform fit: The BT-315 runs a single-cell 3.7V Li-ion architecture with a direct solder or connector tab mount. This cell matches that voltage rail and physical footprint. No BMS handshake is required at the cell level on this unit — the protection circuit sits on the PCB.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on GPS-class hardware. The protection circuit responded correctly to over-voltage and under-voltage thresholds, and the cell held stable voltage across the draw profile typical of a GPS receiver with active display.
• Cold-start satellite acquisition after swap: After fitting this cell, power the BT-315 on outdoors with a clear sky view and leave it to acquire a satellite fix before navigating. A full power interruption triggers a cold start — first fix can take 5–10 minutes. Subsequent starts are significantly faster once almanac data is cached.

GPS accuracy reduced at low battery on the BT-315

As cell voltage drops toward the lower end of the Li-ion discharge curve, some GPS receivers step down receiver sensitivity to reduce current draw and extend available power. On the BT-315, this can show as position drift or slower fix refresh during the final portion of a discharge cycle. The fix is straightforward — charge the cell before long navigation sessions. If accuracy issues appear early in a session, the replacement cell may not have been fully charged before first use; charge to 4.2V at the cell level before fitting.

BT-315 shuts off without warning before the battery indicator reaches empty

The BT-315 fuel gauge is calibrated to the original cell's discharge curve. A new cell with slightly different internal resistance will shift where the voltage-threshold cutoff sits relative to the on-screen indicator. The device hits the hardware cutoff voltage before the visual indicator reaches zero, so the shutdown appears sudden. Run two or three full charge-discharge cycles to allow the gauge to recalibrate against the new cell. If early cutoffs persist after three cycles, check that the cell voltage at shutdown is at or above 3.0V — anything lower points to a cell fault, not a calibration issue.