About this replacement
Asus S102 Multimedia Navigator — 3.7V Li-Polymer Replacement Battery (90WG012AE)
This 3.7V, 1250mAh Li-Polymer cell replaces the original battery in the Asus S102 and S102 Multimedia Navigator portable GPS units. It matches the OEM part number 90WG012AE and the physical dimensions of the stock cell at 58.22 x 36.09 x 4.95mm. Fit it and the navigator powers on as normal — no firmware changes required.
- S102 and S102 Multimedia Navigator compatibility: Both models run the same 3.7V single-cell Li-Polymer architecture with the same connector and BMS handshake. This cell meets that voltage rail and communicates correctly with the onboard charge controller.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the S102 platform. The BMS accepted the cell without fault flags, charge termination triggered correctly at full capacity, and the protection circuit cut off cleanly at the low-voltage threshold.
- First-use cold start note: After fitting this cell, power the unit on outdoors and let it acquire a satellite fix before driving. A full power interruption forces a cold start — expect 5 to 10 minutes for the first fix. Subsequent warm starts drop back under a minute once the almanac data rebuilds.
GPS battery draining faster on active navigation than on standby
Active turn-by-turn navigation runs the GPS receiver and the display simultaneously. The receiver polls satellites continuously and the screen stays lit at full brightness — together these draw significantly more current than standby mode. A worn original cell masks this gap because total capacity is already reduced, so the contrast becomes obvious only when a fresh cell goes in. Reduce display brightness one step and the drain rate drops noticeably on a 1250mAh cell of this size.
S102 shutting off without warning at apparent mid-charge levels
The S102's fuel gauge reads relative capacity based on the original cell's discharge curve. After a battery swap, that calibration is off until the unit completes at least one full charge-to-discharge cycle. Until then, the displayed charge level lags the real voltage, and the device hits the hardware low-voltage cutoff — around 3.0V — before the on-screen indicator reaches zero. Run one full charge cycle, then discharge until the unit powers off naturally to recalibrate the gauge.