Ive got 2 knackered 70ah batteries in my rib at present, would it make any difference if if put 2 85ah in there instead? is it likely to blow something? or would it be even better to replace it with a 110ah?
as you can tell this isnt really a strong point for me!!!
Ah rating is what the battery can supply. Draw is determined by what the accessories (or other loads) pull. Larger rated battery is fine, as long as it fits where it's supposed to.
