new battery bit the dust but could have been worse.

Not knowing what you have installed but it sure take a good short to melt down cables and terminals...

Check the battery wiring for possible reverse connections or the way they are connected especially if you have some 6VC batteries connected in series to make 12VDC.

Something is sure amiss here. The batteries should have catastrophe fuse protection for outside wiring short events...

Your batteries wiring should look something like this for 6V and 12V wiring


be safe out there
Roy Ken