Asus MyPal A630 SBP-03 Replacement Battery 3.7V 1350mAh

Asus MyPal A630 Series — 3.7V Li-ion Replacement Battery (SBP-03)

This is a 3.7V, 1350mAh Li-ion cell that replaces the SBP-03 battery in the Asus MyPal A630, A632, A632N, and A635 handheld GPS navigator and PDA series. These mid-2000s devices run a single-cell Li-ion pack at 3.7V nominal — this replacement matches that spec exactly. Fit dimensions are 52.10 x 39.20 x 7.60mm.

• MyPal A630 series compatibility: The A630, A632, A632N, and A635 all share the same battery bay geometry and 3.7V single-cell voltage rail. The SBP-03 connector and BMS handshake are identical across this range, so one part number covers the full group.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the bench and confirmed the BMS communicates correctly with the MyPal's power management IC — charge termination triggers at the expected cutoff without fault flags.
• First satellite fix after fitting: After a full power removal, the MyPal A630 loses its ephemeris data and performs a cold start. Power the unit on outdoors after fitting this battery and let it acquire a satellite fix before navigating — cold start acquisition takes noticeably longer than a warm start on subsequent uses.

GPS accuracy reduced at low charge on the MyPal A630

The MyPal A630's GPS receiver draws more current than any other function on the device. When cell voltage drops toward the lower end of its discharge curve, the unit reduces receiver sensitivity to protect the remaining charge. This shows up as fewer satellites locked and wider position scatter on screen — not a hardware fault. Keep the cell above 3.6V during active navigation to maintain full receiver performance.

MyPal shutting off without a low-battery warning

After years of use, the MyPal's fuel gauge calibration drifts relative to the actual cell's discharge curve. The device reads the voltage as adequate, displays no warning, then hits the hard undervoltage cutoff threshold and powers off instantly. This is a calibration issue — not a fault with the replacement cell. Run two or three full charge-to-cutoff cycles to allow the power management IC to re-map the discharge curve against the new cell's actual capacity.