Avision MiWand 2 Compatible Battery 3.7V 660mAh

Avision MiWand 2 — 3.7V Li-ion Replacement Battery

This 3.7V 660mAh Li-ion cell fits the Avision MiWand 2 portable document scanner. The MiWand 2 is a handheld roller scanner — you drag it across a page to capture the image. When the original cell loses capacity, scans cut out mid-page or the unit refuses to power on at all.

• MiWand 2 platform fit: The MiWand 2 uses a compact single-cell Li-ion pack at 3.7V nominal. This replacement matches the original cell footprint (40.00 × 31.10 × 5.90mm) and connector orientation so the unit closes fully without pressure on the flex cable.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the MiWand 2 platform. The onboard BMS accepted the cell without rejection flags, and charge termination behaved normally at full voltage.
• First charge on the MiWand 2: Charge the new cell fully inside the scanner via USB before your first scan session. The MiWand 2's charge circuit needs to complete one full cycle to calibrate the capacity indicator — starting with a partial charge skews the remaining-power display for several sessions.

Why the MiWand 2 stops mid-scan on a new replacement cell

The MiWand 2 draws a short current spike each time the internal image sensor fires across the scan line. If the replacement cell has a slightly higher internal resistance than the original, that spike causes a brief voltage dip that trips the low-voltage protection in the BMS. The unit shuts down even though the cell still has charge remaining. This is not a faulty cell — it is the BMS reacting to the dip. Running one full charge-discharge cycle through the scanner reduces internal resistance at the cell terminals and clears the behaviour.

Capacity indicator frozen at one bar after fitting a new cell

The MiWand 2 maps its battery indicator against a fixed voltage-threshold table written for the original cell's discharge curve. A fresh replacement cell sits at a slightly different resting voltage than an aged original, so the indicator reads one bar even after a full charge. This is a display calibration issue, not a cell fault. Charge the unit fully via USB, then run it through one complete discharge before recharging — after that cycle the indicator threshold resets and reads accurately. Resting voltage on a full cell should measure approximately 4.1–4.2V across the terminals.