Magellan RoadMate 9055 Replacement Battery 3.7V 1050mAh

Magellan RoadMate 9055 Series — 3.7V Li-ion Replacement Battery (03B292FJ20301)

This is a 3.7V, 1050mAh Li-ion cell that fits the Magellan RoadMate 9055, 9055LM, RoadMate Pro 9165T, and RoadMate 9020 portable GPS navigators. It replaces OEM part 03B292FJ20301 and restores power to units where the original cell no longer holds a charge. Dimensions are 49.50 × 35.80 × 5.48mm — confirm against your existing cell before fitting.

• RoadMate 9055 and 9055LM compatibility: These models share the same internal battery bay dimensions, connector pinout, and voltage rail. The 9165T uses the same cell under a different chassis label. All pull from the same 3.7V supply with identical BMS communication requirements.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a RoadMate 9055 unit. The BMS accepted the cell without fault flags, charged to full cutoff at 4.2V, and the protection circuit tripped correctly at the low-voltage threshold — no spurious shutdowns during the test cycle.
• First-fix satellite lock after swap: After fitting this cell and powering on, take the unit outdoors before starting navigation. A full power interruption clears the GPS receiver's ephemeris data, triggering a cold start — expect a 5–10 minute first fix rather than the sub-minute warm start the original cell supported.

GPS accuracy dropping at low battery on the RoadMate 9055

The RoadMate 9055 reduces GPS receiver sensitivity as cell voltage drops toward the low-voltage cutoff threshold. This is a firmware-level power conservation measure — the receiver draws less current, but satellite signal acquisition weakens. Positioning errors increase and route recalculations become more frequent. Keep the unit charged above 3.6V during active navigation to maintain full receiver performance.

RoadMate 9055 shuts off without warning before the battery indicator empties

After a full battery swap, the on-screen fuel gauge is uncalibrated — it reads the cell's charge state against the old battery's degraded baseline. The device hits the actual low-voltage cutoff threshold while the indicator still shows bars remaining. This corrects itself after two or three full charge and discharge cycles, which allow the unit's gauge to re-map against the new cell's actual capacity curve. Run it to automatic shutdown twice, charge fully to 4.2V each time, and the indicator will track accurately.