Yes I know the wires a too thin, I will buy #8. Thanks for the advise cleaning the connectors, will do...
Both battery are somewhat loaded (12.4 volt)
When I connect the green (car) battery to the left of the RV batteries the meter jumps from 3-9 volts. I didn't had it connected long, because i am scared to do some damage.
If I connect the green battery the reading on the meter should still be 12 something, right?
Again this is only for emergency purposes. Or maybe, since I have the battery I could hook it up permanently. Or does it hurt when you mix battery types?