2008 PDS won't charge after setting in the garage for the winter

[seasonedjim]

Power Wise Charger doesn't respond when plugged into the cart. Checked the 6 batteries with a volt meter and 4 were 5.67 to 5.72 volts, one was 2.53v and the other 1.66v. The World Wide C12 batteries are probably 7 to 8 years old. (Probably need new batteries) I disconnected the 2 low voltage batteries and connected them in series to a 12v auto charger. The one is now 5.82v and the other only 3.72v. I started to attach the wiring and noticed the voltage of the battery pack is 31.4v. The voltage between the negative battery terminal and the BL- heavy green cable that attaches to it is 30.8v. This doesn't seem right with the key off, F/R switch neutral and the controller switch is in Maintance/tow. 1) How do I teat the charger 2) Is there something else I should check? I don't want to hook-up BL- cable and damage something else. Thanks

[NOLA26]

Most chargers will not start to charge until it detects a minimum voltage from the batteries. Not sure what that voltage is exactly, but I would guess that 30v is too low to engage the charger.