Almost new (6 ish mos) Mustang battery dying

[ezbtr]

After a week or so of sitting, I have a charger that has a "bad battery" light indicator, that does NOT come one, I've jumped it after charging for just a few minutes, I was slow charging it yesterday and those cables were getting pretty warm (but it's 100 degrees where I live) so unhooked it, battery is connected to cars cables still when charging. Bad battery? I've looked for any parasitic discharges (interior lights etc) cant find any, one note, the only thing I did different a few weeks ago was, when I pulled it into garage, I opened both electric windows a bit for air circulation in closed, hot garage and shut car off. Alternator gauge showing good charge.
Ideas? started right up today after running for a few minutes yesterday.

Thanks

 

[DeepCMark58A]

6 month old car with battery issues, get the car running and bring to to the dealer. A warrantee is your friend.

 

[Scott Danforth]

DeepCMark58A its the battery that is new, his car is a 2004 if I recall.

ezbtr have the battery tested, have the alternator tested.

 

[ezbtr]

oops sorry 2006 Mustang GT

 

[ezbtr]

Think I figured it out, when battery died last/possibly replaced, driver side window not going up all the way. found out how to reset it today , we'll see, car (06 Mustang GT 4.6, auto) only has 68K on it, alt gauge looks fine, this battery 6 ish mos old

 

[Old Ironmaker]

Bring the battery back to where you bought it. I have bought batteries that were bad before I put them into the vehicle.