[TrudyM]

Originally Posted by Frozen1

As a pack of batteries is used, or ages, it would be normal for one battery among the others (or one cell within a battery) to become slighlty off capacity of the others. The charger will attempt to equalize that during the finishing stage of charging, which can result in excess hyrdrogen gassing because while bringing up the lower cells, the higher ones will still get somewhat of a boost.

Any vehicle will do it, but not all the time. If it does it at every charge, I would have the batteries load tested in the event of a bad one.

As AJ stated, do not unplug or the pack will never be fully charged and equalized. This may mean let it charge outside one night to get that equalization charge and keep the odor our of the garage where it's also safer. No need to inhale fumes!

Now that makes sense. After reading here we were looking at carts and guys at the golf cart store told him it was normal as well. But the uneven cell explanation makes perfect sense.