I-Tech T-One 2016 Replacement Battery 4.8V 2000mAh Ni-MH

I-Tech T-One 2016 / MAG1000 2018 Series — 4.8V Ni-MH Replacement Battery (220AAH4BMXZ)

This is a 4.8V, 2000mAh Ni-MH replacement battery for the I-Tech T-One 2016 and related electrotherapy units. It replaces OEM part 220AAH4BMXZ and fits the MAG1000 2018, T-One COACH, T-ONE MEDI SPORT, and additional models in the same platform family. Voltage and capacity match the original cell pack exactly.

• T-One and MAG1000 platform fit: These models share the same 4.8V four-cell Ni-MH architecture, connector pinout, and BMS communication protocol. Swapping between units in this family does not require a firmware change or reconfiguration — the battery pack is mechanically and electrically interchangeable across the listed models.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on the T-One platform and monitored the BMS handshake at each stage. The charge IC accepted the cell without flagging a chemistry mismatch, and the pack held voltage within spec across the full discharge curve.
• Post-install self-test cycle: After fitting this battery, let the device complete its full power-on self-test without interruption. The T-One's BMS runs a verification sequence at startup — cutting power during this window writes a fault flag that persists until the next clean reboot, making the unit appear faulty when the battery is fine.

Why the T-One 2016 shuts off unexpectedly during a therapy session

Ni-MH cells have higher internal resistance in the first several cycles after manufacture. The T-One's load profile during active stimulation draws enough current to trigger the BMS undervoltage cutoff on a new cell before the cell is properly conditioned. This is not a fault — it is the BMS protecting the pack. Running three to five complete charge-discharge cycles normalises internal resistance and eliminates mid-session cutoffs.

Device not completing boot sequence after battery sat in storage

Ni-MH cells self-discharge at roughly 1–3% per day at room temperature. A pack that has been warehoused for several months may drop below the T-One's BMS recovery threshold — typically around 3.6V for a 4.8V pack — and the device will not boot or will halt partway through the startup sequence. Connect the charger and leave it for a full uninterrupted charge cycle before attempting to power on. Once the pack recovers above the threshold voltage, the BMS re-initialises and the boot sequence completes normally.