About this replacement
Garmin Nuvi 285 / 285W / 285WT — 3.7V Li-Polymer Replacement Battery (ED26ED2985878)
This 3.7V, 1250mAh Li-Polymer cell replaces the factory battery in the Garmin Nuvi 285, 285W, and 285WT portable automotive GPS navigators. It matches the original's physical footprint at 60.00 × 36.50 × 5.00mm, so it seats correctly in the battery bay without modification. Capacity figure is taken directly from product data — 4.63Wh total energy.
- Nuvi 285 / 285W / 285WT battery compatibility: All three variants share the same internal battery bay dimensions, connector orientation, and 3.7V supply rail. The 285W adds a widescreen display; the 285WT adds traffic reception — neither change affects the battery specification or fit.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the Nuvi 285 platform and monitored BMS behaviour through low-voltage approach. The protection circuit triggered cleanly at the correct cutoff threshold with no premature shutdown or erratic voltage reporting.
- First satellite fix after battery swap: After full power removal, the Nuvi 285 loses its assisted GPS cache and performs a cold start. Power the unit on outdoors with a clear view of sky and allow 5–10 minutes for the first satellite fix — subsequent warm starts will lock in under a minute once the almanac rebuilds.
GPS accuracy reduced at low battery on the Nuvi 285
As cell voltage drops toward the lower end of the 3.7V nominal range, some Nuvi units reduce GPS receiver power draw to extend operation. This shows up as slower position updates or minor positional drift — not a mapping error. The receiver is running at reduced sensitivity, not failing. A freshly charged cell restores full receiver power and normal fix accuracy.
Nuvi 285 shutting off without a low-battery warning
After a battery swap, the Nuvi 285's fuel gauge needs a full charge-to-discharge cycle to calibrate its voltage-threshold indicator. Until that cycle completes, the displayed battery icon may show two bars when the cell voltage is already near cutoff. The BMS then trips the protection circuit and the unit shuts off without the expected on-screen warning. Run one complete charge cycle — charge to 100% on the device, then use it until it powers down — to realign the indicator to actual cell voltage.