Charging problem

I just purchased a used 2008 Gem and the batteries showed that they were charged full. I drove the car for a few miles and ran the batteries down to the red bar.i tried charging the batteries over night but the batteries showed that they were not charged at all. What am I doing wrong.

Batteries will not charge again if they were run too low.

Just got an 02 E825 and am also having charging problems. Dash said they were at 90%. After several tries, they actually discharged to 15% and would not charge. Read about the ALTERNATIVE CHARGING method in ano line owners manual and am currently charging each battery individually with my old auto charger. OLD HOUSEBOAT GUY sent me a service manual just now (THANKS!) So I’m researching the charger issue. Mine may be the charger/battery type issue I’ve seen others discuss