Parallel

Hi Brian
You should not have any problems.
You will have twice the power available but it will take twice the time to recharge unless you increase the input rate.
Ray

Should be ok.
We have 3 x 115ah Deep Cycle batteries in our c/van, charged by either solar (via 3x 64 w pannels and a Plasmatronics PL20 Charge Regulator) or towing vehicle (via an Arrid Twin Charge) or a 3 stage battery chager when mains avail.
This ran a 2 x 12 v fridges, tv, inverter,lights etc for our 2yr trip around Oz.

Have 3x80amp fullriver AGM on c/trailer linked in para to give 240 amp hr ,charging thru vehicle aux also 80amp fullriver AGM as is start batt ,controlled thru A w/ender ROTRONICS regulator [cheap if self fitted] ,,all batts fully charge while driving for even a short time ,1-2 hrs from discharge ,, when camped use solar 1x64 unisolar +1x120 kyocera thru a plasmatronics 20amp regulator , pumps out 10amp per hr on an AVERAGE type of winters day in sth/east Qld ,this runs an 80lt waeco fridge/freezer + an 15lt engle fridge and tops up the c/t batts for night time , my batts never drop below 12.5 volt,, some will dispute ,however system works for me in my situation.

Hi Brian, as previously stated you shouldn't have any problems. For best results use two identical batteries of the same capacity so that equalising beween the two will be even when discharging and charging. I have been running two heavy duty start batteries in parallel for years & haven't had any problems. Cheers.