Just keep in mind that 13.6VDC will start boiling out of fluids over time where 13.2VDC will not do this as much if at all...
If the batteries are already charged I would think anything above 12.6-7VDC would do the trick the maintain them...
The batteries will demand how much current they want to see depending on their charge state. The only reason to have alot of DC CURRENT available would be to be able to charge several batteries in the battery bank at the same time and try to maintain around 17-20AMPS of DC CURRENT per battery if you want to charge them then in a quick three hour time frame. Otherwise it will take longer to charge them.
My maintenance trickle charge is somewhere around 12.5-12.7 VDC and I monitor the battery charge status on a scheduled basis...
I guess what the folks on here are saying if you want the batteries to stay at 12.7-8 VDC you should have your trickle charge at that level or a tad higher...
In my case I guess they are saying my fully charged batteries will eventually drop down from their 12.7VDC level to my trickle charge level of 12.5VDC over time ???
Also alot of folks will get their batteries to a full charge state and then just disconnect them and let them set. When they drop down to 12.5VDC or so over time then re-charge them back up again and disconnect again.
I do this method as well just leaving them sit in the battery box and switch them completely out of the circuit. If they are charged-up they won't be affected by freezing temperatures.
Roy Ken
