Originally Posted by TeraFlex
Signs do point to the battery. It has to be load tested to really ensure if it's good. A battery with a bad cell can show fine voltage but as soon as it's load tested it shows as bad.
Bought a BRAND NEW battery once. Store brand "Federated auto parts" from Ridge And Kramer (local chain) Of course,generally you buy one because of a problem like OP.
Never would start the car quite right. When it did start it would start it slowly. I returned it, they tested it and said it was fine (with a volt meter). They kept my battery for like an hour to do this test.
Still wouldnt start. Went through hell trying to figure out why my car wasnt charging it.
Returned it to another store who actually had a load tester, 10 seconds later i had a new battery. Had a dead cell. Brand new battery. Also, funny thing, a representative from Deka was at the store, and it turns out Deka actually makes these batteries for federated auto parts (which has caused me to buy several more federated auto parts batteries, deka is good stuff...). Apparently it happens sometimes.
Anyway, be careful about the whole battery testing thing. You never know if the auto parts store knows what the heck they're doing either. And just because a new battery doesnt fix it, doesnt mean it wasnt the battery....