Batteries reverse charged

[Papas 73Dart]

I am looking at a neighbour's 2012 Club Car Precedent cart and it wont turn on the charger. When i took my multimeter to check individual batteries. Imagine my surprise when EVERY battery showed a reverse charge. I thought that my leads were plugged in wrong but they were correct. He claims it was running but I can’t see how. .
my question is how do i safely drain then charge the batteries in the correct polarity. Or are the batteries toast??

[Fairtax4me]

Try another meter and/or verify that it is reading correctly a KNOWN good battery.

Next to impossible for batteries to reverse polarity once they’ve been properly charged. If they were incorrectly charged on the very first charge when they are brand new is the only time when they’re most likely the get reversed, and at that it would only be one or maybe two if they were installed backwards. The entire pack would not do that because the charger would trip the breaker and blow all the fuses trying to do that.

There could be a wire issue that’s not allowing the charger to turn on, or the OBC in the cart may have failed if it still has one.

To give any specifics we need to know exactly what charger he uses. Brand and Model numbers.