Battery Suck The Big One!

[EAST SIDE LOW LIFE]

Last night I thought I would start the 70' and warm her up as tomorrow she gets tags and I get to cruze after all the hard work. Well the Battery bit the bullet.

This would not be so bad but I bought it new 4 months ago and it only was putting out 12V & 11.5V with the lights on. (I only used it so far over the winter to warm up the truck, maybe 10 starts in total.) I called the guy today and told him and he said it probably just needed a good run. I put it on my charger and it shows it fully charged. Not enough candle pwr to hardly run my interior light.The old battery I took out of the truck I'm using in my 50' with no problems. I always disconnect the ground cable when not in use over the winter.

Am I missing something here or did I get a bum battery?

esll.