All helpful responses, thanks to everyone. Last time I took my AGM batteries to a local place that said they were the end-all in battery testing they were wrong....they said they were fine, but the batteries were bad. But, I will test them more thoroughly. Paul, that's a great idea. I'll probably take them to our local CC and see what they say.
Jax, I was thinking the same thing...still wondering if my IOTA is butting heads with my controller. I'm going up to Yellowstone tomorrow and will have the camper off landline for a couple days, so I'll see if that makes a difference.
Craig, the one part of your post regarding the absorption charge time.....I have a compatible battery monitor that comes from Blue Sky, IPN Pro Remote. It communicates w/the controller continuously. One of the settings on the monitor is absorption charge time measured by current vs. time, which is called 'Float Transition Current' on the monitor....once the current drops below 1.5A per 100 Ah of battery capacity (or whatever you set it for, this is adjustable), the controller goes from absorption to float. I left the setting on factory default (1.5/100Ah), and my Ah capacity is 230Ah, so it transitions when the current drops below 3.45A. Supposedly it's a better way of transitioning, instead of doing a standard 4 hours of absorption, or whatever the time parameter is. In theory it makes sense, but have no idea how efficient it is in practice.
pv...I couldn't do the swap-out of my 12V truck battery. My connections from the controller to my 6V batteries are via the screw-on 1/2 in. threaded post....my truck battery only has the fatter terminals. I don't have any adapters, so I couldn't do it today.