I have two 12v 130ah Leoch AGM leisure batteries connected in parallel (so I think 260ah total?) and am looking at buying one of the IP65 blue smart charger range. Which size charger would be best for this? Would the 12/15amp one be sufficient? I would like to charge both batteries at the same time if possible (so attach the charger to the positive of one battery and the negative of the other) as they are already connected together but not really bothered about super quick charge time as I will be charging them at home mostly!