Gear: one 235 W poly module, Morningstar MPPT-15 controller, two battery banks-2 X 6v's from Sam;s Club, 3 X 12V AGM's ( two banks total 300AH).
I have the Morningstar controller programmed for 14.6 V absorption and 14.4 V float. This is for off-season storage in MN with the module tilted to around 60 degrees, pointed South. In the Winter, at ice-cold temps, the temp compensation will rise to 14.8V or so. The controller will push the higher voltage for an hour each morning and then go into float if nothing has been drawing them down. I figure the batteries get a pretty good charge in the short days of Winter and the SOC will dip down towards 13 or so volts by morning.
I don't have an equalize session programmed into the controller (although it would be easy to do), choosing to do that manually with my shop auto charger. If I didn't have the bigger auto battery charger, I'd be looking at getting one of the power supplies mentioned. I'm the kind of guy that likes to do battery maintenance manually. I got 10 years, one month out of my original truck battery and that battery saw a highly used life.
I haven't looked at the 6V's specific gravity since last Fall but they went into Winter with a 1.29 or 1.30 SG. In the next week or so I'll check the SG again and probably put the shop charger on them to give everything a good stir. The SG is at the heart of it all, regardless of charge times and voltage levels. Just so folks don't think I'm killing my AGM's, I have the banks setup to be switched in or out when doing an equalize session and the AGM's are telecom batteries that will accept the higher float voltages I use.
