Logitech MX Vertical Replacement Battery 3.7V 180mAh

Logitech MX Vertical — 3.7V Li-Polymer Replacement Battery (AHB521630PJT-04)

This 3.7V, 180mAh Li-Polymer battery replaces the internal cell in the Logitech MX Vertical wireless ergonomic mouse (810-006368 / M-R0074). It powers the optical sensor, scroll wheel, and Bluetooth connectivity. When the original cell degrades, this is the direct swap to restore normal function.

• MX Vertical compatibility: The MX Vertical uses a slim Li-Polymer cell at 3.7V nominal — standard AA or AAA cells will not fit. The 32.20 × 17.20 × 4.72mm form factor matches the original cell cavity exactly, and the BMS on the mouse expects Li-Polymer charge curves, not NiMH.
• Bench tested on actual hardware: We ran this cell through the MX Vertical's charge management circuit and confirmed BMS handshake, correct charge termination at 4.2V, and clean cutoff at the low-voltage threshold — no false low-battery warnings during the test cycle.
• Soldering and connector orientation: The original cell is soldered directly to the PCB — there is no plug-in connector. Transfer the solder tabs carefully from the old cell. Reversing polarity at the pads will trip the internal protection circuit immediately and the mouse will not power on.

Why the MX Vertical won't reconnect after a battery swap

Replacing the internal cell causes a full power loss event, which can clear the mouse's active Bluetooth session. The MX Vertical stores pairing data in onboard memory, but the USB receiver may lose sync if power was interrupted mid-session. After reassembly, unplug the Unifying receiver, wait ten seconds, then replug it. If the mouse still does not connect, hold the Easy-Switch button for three seconds to force a fresh pairing cycle.

Pointer stuttering or tracking lag on a freshly installed cell

Stuttering right after a new cell is installed usually points to a solder joint issue, not the battery itself. A cold or bridged joint on the positive or negative pad causes intermittent voltage drop, which the sensor interprets as a low-power condition — it reduces polling rate to compensate. Check both pads under magnification for a dull, cracked joint. Reflow the joint and confirm voltage at the pads reads 3.7V at rest before closing the housing.