Gem charger issue

My cart has 6 under a year old flooded batteries, recently charger only bringing up to 85%. yesterday cart went from 85% to 30 Percent in 500 feet.
I took all batteries out and charged individually then load tested. all load tested perfectly. reinstalled all batteries and made all connections clean and bright. put cart in garage and plug in, resulting in the led light flashing red. Is my charger done? or should we look at something else?:frowning:

Sounds like it could be a bad battery. Get a Hydrometer and check each cell. Before you chuck the charger.

Does your charge algorithm match flooded batteries?