Topic: how long will my battery box power my mics?

[rhinowing]

I have a SP-SPSB-10 box and SP-BMC-2 and CA-11 mics. The box takes an M21/23 battery. Anyone know the formula for calculating battery life, or better yet the actual numbers? I run the box flat (no rolloff) if it makes a difference.

[ilduclo]

since those batteries are about $2, I'd just replace them every 6 months, this is what I do with my 9v bat box.