batteries

 I have taken the shore power off the camper and the batteries test at 12.67-68. I am going to leave the shore power off for the night and then test in the morning to see if there is any noticeable difference. Thanks for the input again!

Checked the batteries this morning after going through the day without shore power and they are now 12.50 or 87% according to the instrument I have to keep track of the batteries power level? When I took the power off the batteries they were reading 12.68 and 100%. After charging back up to 100% Tonight I am going to turn on the battery disconnect and remove shore power and see what happens. I suppose that if  I leave the shore power on and turn on the battery disconnect the batteries will not continue  to charge?  

Not to confuse things, but I read somewhere that one should not charge AGM batteries with chargers for Lead- Acid batteries.  Could that be part of the problem?  

A little battery 101.

Flooded batteries need higher charge voltages occasionally. Flooded batteries tend to stratify, with the heavier sulfuric acid (lead acid battery electrolyte is a combination of water and sulfuric acid) settling to the bottom leaving lighter water on top. Eventually this can cause damage to the battery.   Once a battery is fully charged additional charging results in electrolysis of the water, creating hydrogen and oxygen. The bubbles this forms mixes the electrolyte and counteracts the stratification. This process is called equalization, and good chargers have an equalization cycle at intervals if you select the flooded battery option.

AGM and gelled electrolyte batteries (generically called valve regulated lead acid batteries) fix the electrolyte in place either by gelling it or absorbing it into glass matt's so they don't stratify and don't need equalization charging.

However, they also have less electrolyte and no way to add more. They are aren't really sealed, just have valves that regulate the internal pressure, hence the name VRLA. The valves are needed to vent the gasses if they do get overcharged. Otherwise they will try to recombine (burn) the hydrogen and oxygen internally, overheat and can explode. Not good. So be sure you do not charge AGMs or gell batts using the flooded battery setting on your charger.

So the pros of AGMs are no stratification and no need to equalize or add water regularly. The cons are high cost and lack of a way to add water if they are overcharged. Not much if any difference in capacity or cycle life.

Hope that helps.