well if the cart has a radio i would guess it has a voltage reducer cause if they are 8 volt batteries the radio won,t run off one and will fry if you try to run 16 volts thur it...................you really need to load test the batteries and yes check them all with a hydrometer, keep in mind even a battery with good voltage can fail under load....and yes i would be concerned with the 2 that are reading under 8 volts......but check all 6 batteries and ckeck cables..............clean and tighten all of them........do you know how old batteries are? post the brand and look at the terminals there should be a letter and a # post that....................letter will be month A=january B=february and so on and the # 1 should be 2001 or 2 should be 2002 and so on.........................................
