I bought a new battery back in late April. It runs down and the charger won't charge it. Took it to where I bought it. They charged it. After a few days I tried to charge it with my charger. The indicator light doesn't come on when the cables are hooked up. Even with a battery tender the light goes out when connected.

I think it has a dead cell. Any other ideas? It's dead already just after a week.
Thanks