Stimulator A1B Compatible Battery 7.2V 2000mAh Ni-MH

Stimulator A1B / Globus MyStim — 7.2V Ni-MH Replacement Battery

This is a 7.2V, 2000mAh Ni-MH replacement battery for the Stimulator A1B, DK7-088-0200, Globus MyStim, and Musculaire Myo therapeutic stimulation devices. It restores power to portable clinical and personal-use electrotherapy units where the original cell has lost charge-holding capacity. Voltage and chemistry match the original specification exactly.

• A1B / MyStim / Musculaire Myo platform: These models share a common 7.2V Ni-MH voltage rail and BMS handshake protocol. The battery connector and cell configuration are interchangeable across this cluster, which is why one replacement covers all four fit models.
• Bench tested on actual hardware: We cycled this battery through charge and discharge on compatible stimulator hardware. The BMS accepted the new cell, completed voltage verification, and held within expected tolerance across the first three cycles.
• Startup self-test after swap: After installing this battery, allow the device to complete its full power-on self-test without interruption. Medical-grade BMS firmware runs a voltage verification sequence at boot — cutting power during this window triggers a persistent battery fault that stays logged until the next clean reboot.

Device not completing boot sequence on a freshly installed battery

The A1B and MyStim run a BMS learn cycle on first power-up with a new cell. If the resting voltage of the new battery sits near the lower end of the Ni-MH acceptance window after shipping and storage, the firmware can flag it as insufficient and halt the boot sequence. This is not a faulty battery — it is the charge IC applying a conservative threshold before it has mapped the cell's actual capacity. Charge the battery fully before first use and attempt boot again; resting voltage should read at or above 7.2V at the pack terminals before powering on.

Charge indicator not reaching 100% on the first charge cycle

On the first charge with a new Ni-MH cell, the device's charge IC applies a conservative current limit and may terminate early if delta-V detection fires prematurely on a fresh cell. This can leave the indicator showing 85–95% even after a full charge duration. Run one complete charge-discharge-charge cycle before relying on the indicator reading for clinical use — Ni-MH cells typically need two to three cycles before the charge IC accurately tracks actual cell capacity.