Suunto X10 GPS Watch Compatible Battery 3.7V 400mAh

Suunto X10 GPS Watch — 3.7V Li-Polymer Replacement Battery (PTC602530P)

This 3.7V, 400mAh Li-Polymer cell replaces the OEM battery in the Suunto X10 GPS Watch and X10 Military GPS Watch. It fits the 32.00 x 24.20 x 6.00mm battery cavity and connects to the same BMS board. Swap it when the original cell no longer holds charge through a full day of GPS tracking and activity recording.

• X10 and X10 Military compatibility: Both watch variants share the same battery bay dimensions, connector pinout, and BMS communication protocol. The PTC602530P cell seats and communicates identically in either housing.
• Bench tested on actual hardware: We ran the cell through charge and discharge cycles on the X10 platform. The BMS accepted the new cell without handshake errors, and the fuel gauge registered correctly after a full charge cycle from near-zero.
• Post-swap charge requirement on the X10: After fitting this cell, place the watch on its charger immediately and charge to 100% before first use. The fuel gauge IC on the X10 loses its reference point when the cell is removed. Without a full charge cycle from near-zero, the percentage readout will be inaccurate and the watch may shut off unexpectedly at mid-charge levels.

BMS cutoff during GPS sessions on the X10

The X10 GPS module pulls significantly more current than the watch draws in standby. During active tracking, this spike can push a degraded or freshly swapped cell below the BMS cutoff threshold before the percentage readout reaches zero. The BMS interprets the sudden voltage drop as a low-cell event and shuts the watch down to prevent over-discharge. A new cell at full charge handles the GPS current spike without tripping cutoff — ensure the cell is charged to 4.2V before heading out.

Watch not pairing with phone after battery replacement

Removing the battery clears the active BLE session stored in the watch's memory. When the watch powers back on, it no longer holds the pairing credentials from the previous session. The phone's Bluetooth stack still sees the old device entry but the watch is broadcasting as a new unpaired unit. Fix this by deleting the Suunto X10 entry from your phone's Bluetooth settings and re-pairing fresh through the Suunto app.