When at home and on shore power, I set the solar controller's adjustable Absorption voltage to a Float value, so it is the same voltage set as my converter at 13.x (varies with temperature)
This is different from when out camping off grid using solar, where you want the Float to come on only after the batteries are fully recharged at the higher Absorb value.
With my Eco-Worthy controller, which does no time at all at the Absorb value, once it gets the batteries there, but drops to Float, I have to set the Float voltage at the Absorb value so there is time in Absorb.
On whether to float or not, "it depends". Trojan says float your AGMs unless you are cycling them monthly or more often. So long- term float is it otherwise.
EDIT--there is also a difference between floating a disconnected battery or not, and "floating" a battery that has some draw on it as with one in an RV even when not being used. (or your vehicle when parked )
Xantrex has that feature in their three- stage charger, where you can turn off the Float stage, and it will just stop after Stage 2. This is for batteries that don't like being floated, which they said included golf cart 6s ISTR.
A blurb on SG, says the higher SG batts such as deep cycles don't like floating so much, but low SG batts such as for standby power use, do.
However, without knowing the exact situation, IMO it is way more likely the AGMs that died in two years reason was from not being recharged to proper full as required. You can only do that if you have the correct measuring instruments--an ammeter for "amps to the battery" (not from the solar controller's display) and a voltmeter at the battery.
AGMs do not self- discharge much but Wets do, and some Wets more than others so it varies how long you can get away with not floating.
With Wets you can float at too high a voltage and "boil" out the water or at too low a voltage and have them sulfate. AGMs will sulfate at too low, but you can't add water if too high.
Setting the float voltage for a long term float means at the proper voltage for the temperature. With day and night temps being different, that means more of a seasonal temperature approach with some common sense or else have some kind of automatic temp compensation.
Solar controllers often have auto temp comp, but hardly any converters do. I have the manually adjustable voltage PowerMax LK model of converter/charger, so I have to keep an eye on what the proper voltage would be as the weather changes. But at least I can keep up with that, where I could not with an ordinary converter.
Obviously, the way to avoid all the complications is to go camping often and cycle the batts often, so there is no long term floating to worry about!
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1. 1991 Oakland 28DB Class C
on Ford E350-460-7.5 Gas EFI
Photo in Profile
2. 1991 Bighorn 9.5ft Truck Camper on 2003 Chev 2500HD 6.0 Gas
See Profile for Electronic set-ups for 1. and 2.
