Akai EWI 5000 Replacement Battery 3.7V 1600mAh

Akai EWI 5000 / 5000 Solo — 3.7V Li-ion Replacement Battery (UF16650ZTA)

This 3.7V 1600mAh Li-ion cell replaces the internal battery in the Akai EWI 5000 and EWI 5000 Solo wind controller synthesizers. It fits the original battery bay and connects to the same BMS circuit that manages charge and discharge for wireless operation. Capacity is 1600mAh (5.92Wh), matching the factory specification.

• EWI 5000 and 5000 Solo compatibility: Both instruments share the same 3.7V single-cell architecture and the same battery bay dimensions. The BMS handshake and connector are identical across both variants, so one cell covers either unit.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the EWI 5000 platform. The BMS accepted the cell without faults, completed a full charge cycle, and held cutoff voltage within spec at the low-end threshold.
• First-cycle conditioning on the EWI 5000: Charge the replacement cell fully before playing wirelessly. The EWI 5000's BMS calibrates its gauge against the first full charge-to-discharge cycle — skipping this can cause the battery indicator to misread state-of-charge for several subsequent cycles.

Why the EWI 5000 shuts off before the battery indicator reaches empty

The EWI 5000's display cutoff and the BMS protection cutoff are not the same voltage threshold. The display may show one bar remaining while the BMS trips at 3.0V to protect the cell from deep discharge. An aged or partially degraded cell sags under the instrument's current draw and hits the BMS floor faster than the indicator predicts. Replacing the cell resets the sag behaviour — the indicator and actual cutoff will align again once the BMS recalibrates through a full cycle.

Battery draining noticeably faster after switching to wireless MIDI mode

The EWI 5000's wireless transmitter draws significantly more current than the instrument's base electronics alone. Continuous wireless MIDI transmission keeps the RF module active, pulling sustained current from the single 3.7V cell. A degraded cell with reduced internal capacity will show this drain rate increase earlier and more sharply than a new cell. If drain accelerated gradually over time rather than suddenly, the cell has aged — swap it and charge to 4.2V before the next session.