Vulcan Rider wrote:
Bottom line: A really LOT of people worry about this when there really is no need. Even if it does only charge to 95%, you still are going to get most of the advantages of AGM...
----------
I have just begun deciding on battery options but here is what I do and do not know (yet).
I need every bit of extra storage and amp hours of an AGM since I rarely plug in. I don't think I am getting 95% out of the built in charger when plugged in or on generator. It is lower, perhaps 75-80% (although I haven't tested it yet and am estimating from the idiot light tester on the wall). Apparently most built in converter chargers will not top off an AGM for a LONG time, if ever. A not too expensive supplementary charger will do the trick.
My alternator will top them off when driving but it takes too long. You can upgrade the alternator but I think there is a way to adjust the output to the coach batteries to speed up the charging process a bit. I will post that when I get the details. It takes a lot of juice to cram that extra load into an AGM both via the alternator and the charger.
I am no tech geek and I am not seeking 100%. I would be happy with 95%. I just need every bit of charge I can get the way I travel. Also, deep cycle batteries are built to be discharged and charged over and over but, if you drain them too low, too often and, if you don't keep them topped off in between, the shorter they will last.
Good AGMs are very expensive (there are lesser quality AGMs for less though). I am hard on batteries. Sometime I think it might be better to get some cheaper open cell and run them to death. I could buy three sets for the price of the AGMs. But, my batteries are under the floor and it would VERY difficult to monitor water levels.
If you don't need the extra storage and life out of an AGM battery don't invest in them. If you do need it you may need a supplementary charger and a look at your alternator to get their full benefit and life span.
