I know there's lots of threads on this general topic, but I can't find one that addresses this specific question. Why is the voltage reading different when the batteries are disconnected from the coach verses when they are connected? When I disconnect the batteries and test them with my multimeter they each (two of them) read 12.69 volts. When I connect them to the coach (which has a converter) they read 10.54 volts. (Using the same multimeter for all tests.)
How much current are you pulling when you are connected.
It looks like you have weak batteries or you are pulling a lot of current.
If you only have the minimum turned on in the coach you should only see a couple tenths of a volt change.
Those readings in my original post were taken at the battery terminals. When the batteries are plugged in I get the same reading using a cigarette plug voltage meter in a socket inside the coach.
When I plug into shore power the readings go up to 13.63 at both the batteries and plug.
Happy Vibe: Everything is turned off, so the only things that should be using current (that I can think of) are the CO/Propane detecter, TVs in their off condition, and the clock in the Magnadyne entertainment center.
If the batteries are good and fully charged it would take a vary large current draw to bring them down to 10.5V. so if you have the batteries on and reading 10.5V and then turn them off how fast does the voltage return to 12.6ish volts?
Happy Vibe: the voltage goes back up immediately - the amount of time it takes to flip the disconnect switch and get the multimeter probes on the terminals.
I have two trains of thought. 1 you have a defective battery that has high internal resistance so as soon as you put any load the voltage at the battery drops or you have something in the RV that is drawing a lot more current than you think. The pulling fusses should tell you if it is the latter.
Ontario
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