Mitac Mio Spirit V505 TV Replacement Battery M1100 3.7V

Mitac Mio Spirit V505 TV / V735 TV — 3.7V Li-ion Replacement Battery (M1100)

This 3.7V 1100mAh Li-ion cell replaces the internal battery in the Mitac Mio Spirit V505 TV and Mio Spirit V735 TV portable GPS navigators. Both units share the same battery bay dimensions, connector, and BMS handshake, so one cell covers the pair. Capacity matches the original at 1100mAh (4.07Wh) — no modification needed.

• V505 TV and V735 TV compatibility: Both models run on the same 3.7V platform with identical connector pinout and cell footprint (49.88 × 36.22 × 5.88mm). The BMS in each unit accepts this cell without any firmware flag or error state.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the V505 TV platform. The BMS accepted the cell cleanly, charge termination triggered at the correct voltage, and no low-battery false-positive flags appeared during the test run.
• Cold-start satellite acquisition after swap: After fitting this cell and powering on, take the unit outdoors before first use. The GPS performs a cold start following full power removal — first satellite fix typically takes 5–10 minutes. Subsequent warm starts drop back under a minute once almanac data is cached.

Why the Mio Spirit V505 TV shuts off without any low-battery warning

The battery indicator on the V505 TV reads the cell's state of charge through voltage sampling, not coulomb counting. After years of use, the original cell's voltage curve flattens and then drops sharply — the unit reads "sufficient charge" right up until the cell hits the BMS cutoff threshold. A fresh cell restores a predictable voltage curve, so the indicator has enough headroom to show depletion before shutdown. If the issue persists after swap, reset the device fully and allow two complete charge cycles to let the BMS recalibrate its threshold readings.

GPS accuracy dropping noticeably during long navigation sessions

Some GPS receivers in this class reduce RF front-end sensitivity as supply voltage falls below roughly 3.5V to protect core processing. This lowers the number of satellites tracked, which widens the position error. The symptom appears as route snapping errors or a position dot drifting off the road. Keeping the cell charged above that threshold — or connecting USB power during extended trips — keeps the receiver running at full sensitivity.