i had to replace mine last year. had the original panasonic 1 which was 10 years old! you have to get one the same size or the terminals are too big.i can see you got lead space on the ground terminal because the even the small size batteries arent perfect. it up to you if you want a larger battery, changing the terminal is not that difficult. i can tell you now a good qaulity batteries are not cheap. mine cost me £65 for the right size one! considering normal batteries were £30 back then. The small battery will hold enuf charge (if good quality), i got a clifford which sucks power, and it snowin hard down here in luton and i have had no probs. but you could get a larger battery which are normally cheaper and upgrade the terminals, might cost less. but even with this the battery clamp will need modifying! decisions, decisions..............................