month old battery dies for second time, should I return it?

Something is "on" and draining your battery overnight. Check the trunk light, glove compartment light, any appliances you installed such as a cell phone charger, etc. If nothing turns up, remove some fuses to isolate the drain.

Could be a bad battery, or it could be that your charging system has a problem, or maybe there is a load somewhere (trunk light?) that is draining the battery overnight.

Check the charging circuit with a voltmeter. Nominal battery voltage is about 12.6V, with the engine running at 1500 RPM you should measure about 14V across the battery terminals. Then with the engine off, put an ammeter in series with the battery. If you see any significant current drain (more than 50 ma or so) then search for the cause of the load.

Don't have a voltmeter / ammeter? You can get a perfectly usable one at Sears for about $10 on sale:

What could it be? The last time I used my car before the problem started was just to move it from one side of the street to another. There is no trunk light, the overhead light is off and last night when I left my car I looked all around it to see if there were any lights on. Other than the lights what else could be on?

Another thought: Maybe the battery isn't getting charged properly. A slight drain could take it below the amount needed to start in the morning. I had a very similar problem about 25 years ago and in the end, it was due to a loose alternator belt!

Probably not the battery, although it could be. Why did you replace the other battery and how old was it?

Most batteries returned in the first month are fine, it's usually the rig's alternator, or something else as had been mentioned....by the way, I learned this the "hardway" a couple of decades ago after I went through 3 cheapie K-Mart batteries in a few weeks....

Nowadays, I buy better batteries, but nothing will work if it isn't getting the proper charge or is being slowly drained of life....

I replaced it because it died as well. It was over 4 years old though. the battery the guy gave me to replace it was smaller than the old battery - buy about 20%. I mentioned it to him and he said that was the replacement in the computer. I didn't think he knew what he was talking about. I talked to another guy at Autozone and he said that could be the problem. He said it might not provide the right amount of juice. But then wouldn't it at least put the lights on or allow the power locks to work?

More important than the perceived size is the group number. A '90 camry should have a group 35 battery and that number should be obvious on the case.....other's could work, but a 35 is standard and if you got another size, it might be worth investigating. However, as mentioned, there are a number of more likely scenarios....

I've seen leaky capacitors in factory radios cause these symptoms, although I must admit it is much more likely that you got a bad battery or have a bad alternator / charging circuit.

Instead of speculating you need to measure the current draw from the battery to see if there is a load on it, or not, and check the charging voltage to see if you have a charging problem.

Autozone batteries have a high failure rate so you could have a bad battery. They will check your charging system, starting system and battery for free if you drive the car to them. If a battery is completely dead and you put a fast charge on it, it will sometimes only put a "surface charge" on it which won't last. You need to slow charge some batteries to get them up to full charge, appx 12.6V. davidj92

David thanks for the advice, I took the battery back to Autozone today and they checked my entire charging system and everything was ok except for the battery! It was an economy battery that had somewhere in the

500 range for cranking amps. I upgraded to a battery that did about 700. They took it back and the guy told me he takes a lot of those batteries back. I asked him why they sold them and he couldn't tell me. I assume those batteries are probably fine for warm weather climates but can't hack the cold weather. Anyway, I drove it home today so we'll see if it starts tomorrow.

yeah, my car is one that gets driven less than a mile to the post office, and back, out to walmart, to the drugstore, etc

every so often, I take it on a drive over to OK state line and back, about a

20 mile trip, to charge it up good.

I have a guage package (1991 Dodge Dynasty), so I can tell when the battery is "low"