Magellan Maestro 4300 GPS Replacement Battery 3.7V 1500mAh

Magellan Maestro 4300 / 4350 / 4370 — 3.7V Li-ion Replacement Battery (SMPWGPS1)

This 3.7V, 1500mAh Li-ion cell replaces the original battery in the Magellan Maestro 4300, 4350, and 4370 portable GPS navigators. It fits the same battery bay, connects to the same three-pin board connector, and works with the device's existing charge circuit. Capacity matches OEM spec at 1500mAh (5.55Wh).

• Maestro 4300 / 4350 / 4370 platform fit: All three models share the same chassis width, battery bay depth, and charge IC. The cell draws power through the same voltage rail at 3.7V nominal, so one part number covers the full trio without adapter or modification.
• Bench tested on actual hardware: We ran this cell through the Maestro charge cycle and confirmed the BMS accepted charge handshake without error flags. Voltage held at 4.18V at full charge and the protection circuit tripped correctly at the low-voltage cutoff threshold.
• Cold-start satellite acquisition after swap: After fitting this cell, power the unit on outdoors in open sky and leave it running until it acquires a satellite fix. The GPS performs a full cold start after any complete power interruption — first fix after a battery swap takes 5–10 minutes. Subsequent power cycles return to a warm start, which is under a minute.

GPS accuracy dropping at low battery on the Maestro 4300

As cell voltage falls below approximately 3.5V, the Maestro 4300 reduces current to the GPS receiver module to extend available power. Lower receiver sensitivity means the unit holds fewer satellites and position accuracy degrades — you may see the blue dot jumping or route recalculations increasing on a nearly flat battery. This is firmware-controlled behaviour, not a fault with the cell. Keeping the battery above 3.6V during active navigation maintains full receiver sensitivity.

Maestro 4300 shutting off without a low-battery warning

After a battery swap, the device's fuel gauge is uncalibrated — it has no charge history for the new cell. The Maestro reads estimated state-of-charge from a voltage curve, but that curve drifts until the gauge relearns capacity. The result is a hard shut-off at what the device thinks is its cutoff threshold, while the battery indicator still shows one or two bars. Run two full charge-to-discharge cycles and the indicator will re-align to the actual cutoff voltage of 3.0V.