Any ideas on how to fix a dead Zeus battery

[JoAnna1010]

Yesterday I used my new, titanium Zeus batteries for the first time.
One worked just find. The other was dead and doesn't seem to charge when placed on the charger.

Anyone have any idea what could be wrong with the damn thing??
What could I try to do to fix it ??

I'm not sure if it is still covered by the warrenty even though I hadn't used it until yesterday.

Thanks for your help