Nieuw BT77 Bluetooth GPS Replacement Battery HXE-W01 3.7V

Nieuw BT77 Bluetooth GPS Receiver — 3.7V Li-ion Replacement Battery (HXE-W01)

This is a 3.7V, 1000mAh Li-ion cell built to the HXE-W01 specification, replacing the original battery in the Nieuw BT77 Bluetooth GPS Receiver. The BT77 is a compact portable GPS unit used for outdoor navigation, vehicle tracking, and route guidance. Voltage and capacity match the original cell — 3.7V nominal, 3.7Wh total energy.

• BT77 platform fit: The BT77 uses a single flat Li-ion cell at 3.7V to power both the GPS receiver module and the Bluetooth radio simultaneously. Swapping to a cell with the same voltage and footprint — 52.96 x 33.64 x 5.15mm — keeps the internal connector seated and the BMS handshake intact.
• Bench tested on actual hardware: We cycled this cell through charge and discharge with the BMS under active GPS and Bluetooth load. The protection circuit held cutoff voltage steady and did not trip on the combined receiver-plus-radio draw.
• First fix after fitting: After fitting this cell, power the BT77 fully on outdoors before use. A complete power interruption clears the receiver's ephemeris data, triggering a cold start. The first satellite fix can take 5–10 minutes outdoors — this is normal and not a fault with the replacement cell.

GPS accuracy reduced at low battery on the BT77

As cell voltage drops toward the BMS cutoff threshold, some GPS receiver modules reduce RF front-end sensitivity to lower current draw. On the BT77, this can appear as position drift or reduced fix accuracy before the unit shuts off. The receiver is still acquiring satellites, but the signal-to-noise margin is tighter. Keep the cell above 3.5V under load if accuracy is critical — charge when the low-battery indicator first appears.

BT77 shuts off without warning during active navigation

This usually means the battery indicator is uncalibrated against the new cell — the unit reads remaining charge from a voltage curve tuned to an aged original cell. The replacement cell holds a flatter discharge curve, so the percentage readout stays high longer and then drops fast. The BMS cutoff fires before the visual warning registers. Run two full charge-discharge cycles on the new cell and the indicator will recalibrate to the correct curve — cutoff on the BT77 BMS triggers at approximately 3.0V.