Judging/comparing Battery Performance
We've all read about person X who does nothing more than plug in their converter and claims the batteries are just as good as new 6 years later, although this is an impossibility. More accurate wou...
Forum Discussion
BFL13 wrote:
Those with small RVs which have less space/weight room and use AGMs seem to get by ok according to their reports here. They must know some secret stuff about how to tell what is really going on with an AGM. Can any of them share the secret?
Our 24 footer Class C has two 7 1/2 year old 100AH AGM batteries in it charged almost entirely only by the 13.8V converter or the alternator. The label on the batteries says to float them with between 13.5V and 13.8V. So, I guess I'm both charging them and floating them with the converter most of the time. They "never" sit undercharged for long, as when in storage at home I always have the converter powered and connected to them except in warm weather during storage.
I know close enough how empty they were when I start charging them by noting how much current they are accepting whenever I first put them onto either the converter or the alternator.
When being used for camping and thus not being charged by either the converter or the alternator, I know close enough how empty they're getting by watching the four-place voltmeter that constantly monitors the RV's 12V circuit. As a side note, the four-place voltmeter declines 0.01 volt with each LED interior light we turn on ... the point being that you can keep a pretty good eye on they're condition with a XX.XX resolution voltmeter.
FWIW, I consider it not too important if I take them down to 12.1 volts or down to 11.9 volts before I start charging them. So far this approximation guestimate approach has gotten 7 1/2 years out of these batteries.
