CompM4 Batteries

The CompM4 and CompM5 were specifically designed to use an alkaline battery by request of the original customer (US Army in the case of the M4).

Alkaline batteries tend to have problems with leakage when they deplete their charge. If you are not under a travel restriction or have issues shipping or receiving lithium batteries, I would recommend using a high-quality lithium battery (AA or AAA). They are much more stable.