Bob B wrote:
The other thing I am confused about is the # of charge cycle for various batteries.
There is a local battery manufacturer (Firefly) who has a group 31 agm battery and say it is good for 3600 charge cycle at 50% discharge.
These batteries are VERY expensive, but the cost / charge cycle could actually be less if you are in it for the long haul.
I don't know what # of charge cycles a good flooded cell golf cart battery would be.
The number of charge cycles is a very nebulous number as it depends a great deal on care, circumstances, and conditions. I would be extremely skeptical of a claim for any lead acid battery of 3600 cycles to 50% depth. 500 or 1000 is a more typical claim. AGMs will not necessarily last more cycles than well cared for high quality flooded batteries. The claims even for LiFePO4 batteries are only about 2000 cycles, and they are considered to be far longer lasting than any lead acid.
My expectation would be about the same number of cycles from well cared for flooded and AGM batteries, where both were set up with a good temperature compensated 3 or 4 stage charger. Under those conditions, the AGMs will take less maintenance, recharge a little quicker, not outgas or corrode their terminals or anything around them, and stay charged much better over storage periods. The flooded cells will require more maintenance, cost less, and stand more abuse in the form of under or overcharging.
I will note that good quality flooded cells cost quite a bit more than cheap ones, and are closer to the price of AGMs. If cost is the most important issue, then you have to look at watt-hours delivered per dollar spent, and cheap flooded cells probably win, if you are willing to put up with them. They don't last as long but the don't cost much. And there is no point in paying for AGMs unless the charging system is properly set up to take care of them.
