hey Brian , i don't have the battery for the minelab ( i have it for the dfx and the tdi sl) but i do know a couple of fellas that do and i don't belive it will void the warranty. when you by the battery it does come with a charger and i believe a car charger that plugs into the lighter socket as well. this battery will last far longer than the stock one plus it charges in just a couple of hours instead of overnight like the regular one. i can run my dfx for almost 40 hours on one two hour charge , i'd recommend getting it Brian.
Dan