Originally Posted by mandolindave
You should test the health of your batteries.
#1 Get a cheap plug in 12 volt
meter, or a hand held volt meter.
#2 Plug in RV to shore power. ( an AC outlet )
#3 Check that the charger is working by looking for 13.8 volts ( results vary depending on what charger you have )
#4 Let the batt charge for 8 hours
#5 Unplug your RV from shore power. Check to see if voltage is over 12.8
#6 Don't use any 12 volt
device…let RV sit for a day or two. Eliminate any phantom draws of electricity
#7 Check for " Resting Voltage " Normal resting voltage ranges fro 12.6 to 12.8
Much less than 12.6 resting voltage indicates that your batts need replacement sooner or later.
You might have a faulty battery monitor. You might have a phantom draw ( propane monitor, radio etc ) Your batteries might be done. You might need a new charger. It might be operator malfunction ( Read up on batteries )
Not bad except your voltage points are not correct, assuming that the Interstate has Lifeline AGM batteries.
The inverter/ charger (hopefully a Magnum MMS-1012) should be bulk charging the AGMs at 14.2 VDC.
After charging, remove the negative battery terminal to eliminate ALL loads on the batteries and Allie them to 'test' for 4 hours minimum.
After resting, the no load voltage should be at 12.8-13.2 VDC.
If lower, your batteries have lost their charge retention capacity.
Lifelines are covered by a 5 year pro-rated warranty but this does not apply to poor battery charging habits or allowing the batteries to sit for long periods in a discharged state.