REchargin the battery problem help a.s.a.p.

[Ratchet]

a reg 9 volt will not ruin the circut. i'm an electronic engineering tech. the reg 9 volts even have less voltage, thing is they cant run the circut effectivly thus causing the gun to not work to its full potential. it will work for a while but then die out shortly.
i have always charged my gun while the switch is off (no lights on the trigger are on) i let it charge for about 5 hours after everyuse.sometrimes i uise the gun for 8 hours. you cant overcharge the battery, ive had mine charge for over 24 hours. you may just have a broken switch if nothing else works that you try. is the switch hard to turn on? if it doesnt have a little resistance the switch could be broke. also is the charger all the way into the chargeing port? i have had the charger port thingy be hard to shove the charger all the way in.