About this replacement
Minelab WM-10 / WM12 / GPZ 7000 — 3.7V Li-Polymer Replacement Battery (0303-0036)
This 3.7V 1100mAh lithium-polymer cell replaces the original battery in the Minelab WM-10 and WM12 wireless audio modules, as well as the GPZ 7000 detector. It matches the OEM part number 0303-0036 and fits the compact 51.50 × 34.40 × 6.00mm cavity inside the module housing.
- WM-10, WM12, and GPZ 7000 shared pack: All three units run the same 3.7V single-cell architecture with identical connector pinout and BMS handshake thresholds. Minelab standardised this cell across the wireless module range, so one replacement covers all listed variants without modification.
- Bench tested on actual hardware: We cycled this cell through full charge and discharge on the WM-10 module. The BMS accepted the pack without error flags, held the cutoff at the correct low-voltage threshold, and the module maintained stable wireless audio pairing throughout the test discharge cycle.
- First-use initialisation on the WM-10: After installing this cell, run the WM-10 through a full charge-to-100% cycle before heading into the field. The module's charge controller maps the new cell's capacity curve on the first complete charge, and skipping this step causes the LED indicator to report low charge prematurely during your first detection session.
Why the WM-10 drops audio link mid-session after months in storage
Lithium-polymer cells left unused below approximately 3.0V enter a deep-discharge state where the internal BMS latches off to prevent cell damage. When the WM-10 is pulled out after a long off-season, the module may power on briefly then drop the wireless audio link as the BMS detects the cell voltage sitting at or below its recovery threshold. This is not a fault with the module's RF circuitry — the cell simply needs a slow recovery charge before it will sustain normal operating load. Connect the module to a low-current USB charger and leave it for at least two hours before attempting to pair.
WM-10 LED flashes low-battery immediately after a full charge
When a new or deeply discharged cell is installed, the module's charge indicator reads voltage against a stored threshold calibrated to the previous cell's age and internal resistance. A fresh cell at 4.2V can still trigger an early low-battery flash because the threshold map is out of sync with the new cell's characteristics. Run one complete charge cycle — charge fully to 4.2V, use the module until the automatic cutoff, then charge again. After that single recalibration cycle the LED indicator tracks the new cell accurately.