[Shane826]

You’re trying to read volts but you’re on the amps setting for your multimeter. That’s kinda like trying to measure velocity with a bathroom scale! I kid, I kid.

Put the multimeter to DC Volts (V with a straight line over it) setting. I’d you don’t have an auto ranging multimeter, set it to the 20 DCV range. Regarding an auto ranging meter, let me quote Camco… If you don’t have one, you should get one. Red lead to positive terminal of battery #1, black lead to negative terminal of battery #2. You should be seeing the voltage of the two batteries together in series.