Originally Posted by StephensNC
I will apologize in advance for asking a question likely answered many times before though I have been unable to find those answers.
I have purchased a 2014.5 Interstate, replaced the house batteries with new AGM's, and all seems to be working well. However, I am unclear about the information provided on the various monitors particularly how to know when the batteries are in fact fully charged. Can someone point me to what I need to read to get up to speed? Thanks!
Jim - I can understand your frustration. There are three ways to read the battery voltages and it can be confusing. The only way to get an accurate state of charge is by open circuit voltage of your batteries as described in the attached page from the Lifeline battery manual.
Unfortunately you can't get that accurately without completely disconnecting your batteries and placing a volt meter across the terminals. But you can get close.
The solar control panel readings are the least useful because this meter is not accurate and if you read it when the sun is shinning it just gives you the charge voltage.
The voltage readout for the battery voltages, selected buy the switch on the tank monitor is useful if checked when not charging and everything turned off.
Another option is the Magnum inverter/charger control panel display. The voltage shown is also accurate.
Start by fully charging your batteries by being plugged into shore power overnight. Then the Magnum display should show "Float" and a voltage of 13.4. Then stop charging by unplugging in the dark so there is no solar charging. Have everything turned off, use a flash light to see what your doing. The voltages shown then on the Magnum display and tank monitor panel should tell you your state of charge based on the attached page as close as you can with what Airstream provided.
Hope this helps,
- - Mike
2013 Lounge EXT on 2012 Sprinter