I saw some 12V rechargeable batteries at Academy sporting goods store(a chain). They were used for Moultry automated feeders. They were 7AH, and may be too big for a 7.62mm ammo can. I think the cost was about $15.00 You would also need a battery charger.
I been messing around with some 9 v batteries
by hooking them in a series
from batt A + to batt B -
and batt A - and batt B + to the ms20
I have been measuring around 15 to 16 volts this way WILL IT WORK or NOT?
it to much voltage ?
wonder how long batts will last