My brother gave me his Terra crusher it's e start it last ran about six years ago. His wife is a pain so don't have much help getting it going he put a dyna-sport 1500mah batt on back for estart. Since it's been 6 years batt flat. So bought what I thought was right charger butt charges for sec then say it's charged. But won't even click. Engine free any ideas on batt to buy. . I collect ww2 army trucks no clue about this other then I have seen it run any help would be awesome