Batboard

Is there a way to disable the low battery beep on a MinII? Our FD has one that will activate the beep for no reason with a new battery in it. I resoldered all connections and cleaned the power switch contacts. I also "push and jiggle" testes all traces and even used component cool spray to try to contract the board and nothing.
If there were a way to disable the low battery alert, that would be just fine. Our department doesn't want to spend anymore $$ on the old MinII's.