Perfect, thank you!Yes that is fine. You will get a short if you put the electrode across a gap between two cells in series, but otherwise you will be fine. Look at where the red wires go on the cells and put the electrodes on the part of the cells where they are, They should alternate from one side to the other.
If you can, try and force the multimeter to read volts. I don't like these auto detect modes.
I found another mutimeter and it can read volts, with no auto detect.
B1: 0.1 volts
B2: 0.1 volts
B3: 3.8 volts
B4: 7.6 volts
B5: 11.5 volts
B6: 14.6 volts
B7: 18 volts
B8: 22 volts
B9: 3.3 volts