Help Diagnosis Battery(?) Issue

Hey guys, the gf has a 2011 Toyota Camry (~40k miles) and I was hoping someone on here could help diagnosis an issue...

We went on a two week trip recently and upon returning home (to winter-y chicago), her car had zero juice. No dome light, door chime, remote unlock, nada. I figured it had just drain itself sitting there in the cold for two weeks. Put jumper cables on it and it fired right up. Drove it around for a while and parked it. Didn't start it again for two days, but it started right up when she did. However a day or two later, completely dead again. Took it to Autozone and the tester showed a bad battery, so she got a new one. Problem solved for about a week.

Now today, car starts fine and she drives it two hours, lets it sit for 5-6 hours, and comes back out to a completely dead car (again, no dome lights, remote unlock, etc.)

Any ideas? Could the new battery they gave her have crapped out already? And since she comes out to it COMPLETELY dead it makes me think there is a disconnect somewhere, but jumping it works fine?

 

All the other forums I'm reading keep hinting at parasitic drain on the battery, but that doesn't seem to be the case either. Seeing as how it was parked for 10+ hours last night and started just fine this morning. Then craps out after 5 hours of sitting today

 

Yeah i was thinking loose connection too, but then AAA came and tested the "new" battery and it had a bad cell. So they replaced it again (AAA also put the first one in). We'll see how long this one lasts...

 

Justin, a bad cell will definately keep a new battery from recharging as will a unhealthy charging system. The most common cause of what you described is battery post or terminal lug corrosion. Loose or corroded ground connections will also cause the same symptoms. Most auto parts or battery stores will test your battery or charging system for free and it only takes a few minutes.

 

Thanks for the reply - she has AAA so they did a battery and alternator test for her. The alternator tested good and the battery bad, so I'm hoping it was just a crappy replacement battery they gave her the first time.

 

Justin, is the new replacement battery in your wife's car staying fully charged based on her driving habits? If not, I would suggest that you periodically "top it off" with an external battery charger to prevent the gradual sulfation buildup.

 

Yeah, it's staying charged and the second replacement battery from AAA seems to have fixed the problem. Thanks for the input!