Pharos Drive GPS 200 Replacement Battery 3.7V 1200mAh

Pharos Drive GPS 200 — 3.7V Li-ion Replacement Battery (TM523450 1S1P)

This is a 3.7V 1200mAh Li-ion cell for the Pharos Drive GPS 200 (PDR200) portable navigation device. It slots directly into the battery bay and restores power to the GPS receiver, display, and route guidance system. Dimensions are 52.95 × 34.90 × 6.30mm — verify these against your existing cell before ordering.

• Drive GPS 200 and PDR200 compatibility: Both model designations reference the same hardware platform. They share the same battery bay dimensions, connector polarity, and 3.7V single-cell architecture — one cell covers both.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the Drive GPS 200 platform. The BMS accepted the cell without error flags, and the protection circuit tripped correctly at the low-voltage cutoff threshold.
• Cold-start behaviour after battery swap: After fitting this cell, power the unit on outdoors and let it acquire a satellite fix before driving. The GPS performs a cold start after any full power interruption — first fix can take 5–10 minutes as the receiver rebuilds its almanac. Subsequent warm starts are under a minute.

GPS accuracy reduced at low battery on the Drive GPS 200

As cell voltage drops toward the low end of the 3.7V nominal range, some GPS units pull back receiver sensitivity to reduce current draw. On the Drive GPS 200, this can show up as position drift or a wider accuracy radius on the display. It is not a firmware fault — it is the receiver managing power. Keeping the battery above 3.5V under load maintains full receiver performance.

Drive GPS 200 shutting off without a low-battery warning

The battery indicator on the PDR200 is calibrated to the original cell's discharge curve. A new cell with a slightly different curve can cause the device to hit its voltage cutoff before the on-screen warning reaches empty. This is a calibration drift, not a fault with the replacement cell. Run two or three full charge-discharge cycles on the new cell — the indicator will track the actual voltage more accurately after that.