Battery/ies keep dying

[musntgrumble]

Hi. Almost got my c5 all sorted now but last bit Im struggling with. Ive charged up an old leisure battery went 100 yards then the led indicator dropped went down to 1 bar . I took the terminal connector off and it went up to full bars so off I went again .. same story. Tried another battery a 85 amp leisure same story again down to 1 bar then full again when I got back (including a beep on pod) Im totally lost I can understand one being shot but not 2 and to behave like this is very odd - any ideas ?

[musntgrumble]

When I removed the original wiring to replace it with push on terminals I was left with a thin brown wire which went into the battery area  should I connect this to the negative side terminal on the battery too is that the problem ?

[radiomarty]

This may well be the issue - it is a postive 12v connection that goes to x5 on the control box 

PS - Blue Negative , Brown positive

[musntgrumble]

Thanks Radiomarty your a lifesaver and a control box saver too