Blumax Bluetooth GPS-4013 Compatible Battery 3.7V 1000mAh

Blumax Bluetooth GPS-4013 / GPS-4044 — 3.7V Li-ion Replacement Battery

This 3.7V, 1000mAh Li-ion cell replaces the original battery in the Blumax Bluetooth GPS-4013 and GPS-4044 portable GPS navigators. Both units share the same battery bay dimensions (52.96 x 33.64 x 5.15mm) and voltage rail, so one cell covers both models. Capacity matches the stock specification from Blumax — no inflation, no guesswork.

• GPS-4013 and GPS-4044 compatibility: Both models run the same 3.7V single-cell architecture with an identical battery footprint. The connector orientation and BMS charge profile are the same across both units, so the cell seats and communicates correctly in either device without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on GPS-class hardware. The BMS held the cutoff voltage correctly, accepted a full charge without thermal event, and delivered stable output across the discharge curve without unexpected sag at low state of charge.
• Cold-start tip after fitting: After installing this cell, take the GPS outdoors and power it on with a clear view of the sky. A full power interruption wipes the ephemeris data, triggering a cold start — expect the first satellite fix to take 5–10 minutes. Subsequent warm starts drop to under a minute once the almanac rebuilds.

GPS-4013 Shutting Off Without Warning at Low Battery

After a battery swap, the on-screen charge indicator may not accurately reflect the actual cell state of charge until the device completes at least one full charge-discharge cycle. The GPS-4013's voltage threshold for the low-battery warning can read optimistic against a new cell, so the unit hits its cutoff voltage before any visual alert fires. Run one full discharge to empty and charge to 100% to let the firmware recalibrate the indicator. After that cycle, the low-battery warning should appear at the correct threshold — typically around 3.5V on the cell.

Saved Routes Missing After Battery Replacement

Some GPS-4013 and GPS-4044 units store user waypoints and saved routes in battery-backed volatile RAM rather than flash memory. When the battery drops to zero — or is physically removed — that RAM loses power and the stored data is erased. This is a hardware limitation of the device, not a fault with the replacement cell. Before swapping the battery, export any saved routes or POIs through the device's backup menu if that option is available, or note them manually.