Battery charging problems

I have a ring spotlight cam, battery powered. Problem is with the batteries, not the unit. The charging cable that came with it never did work- wouldn't ever charge, or even light up the battery indicator lights, so I have always used another cable to charge the batteries with no issues, until now. The battery's indicator lights say they are charged, but when I put them in the camera, the camera indicates they are both dead....I do not have another camera to test if it's the camera or just the battery units. My batteries are only about 6-months old. Anyone else ever have this kind of battery problem?