Thread: 4 bad batteries in 4 months, what gives?

So I replaced the battery last summer, since then I've replaced the batter 2 more times and the current battery is doing the same thing. So I already know I'm going to go have the parts store test it, say it's bad, and warranty it out. No big deal, except that I'm tired of going out in the morning and the car not starting. The car can sit at work all day and start fine, it's just when it sits over night that I have problems. The parts store says the alternator is good so I'm stumped. Any ideas? From what I've found only a few things cause batteries to go bad. 1) age, 2) vibration, 3) constant undercharging, and 4) constant overcharging. I know it's not age, it's mounted in the factory location so can't see how vibration is a factor, if it was undercharging the car would never start, and the voltmeter says 14ish volts when the car is running.

Any input would be great.

sounds like your alt is going.

Here is an easy way to test if you don't want to take to autozone to get a load test done.
Take a DMM to the alt output post if less then 13.8 that is a sign that the alt is going
Then using the same ground point. move the pos to the battery terminal with car still running and see what the voltage it should be with in less then a half a volt of the voltage you just saw at the alt.

Also a good way to test for a drain(if your DMM is rated to at least 10amps) is to undo the positive terminal from the battery set your DMM to the highest amp setting usually unfused portion of the input jacks. Then take the positive lead to the battery post and the negative lead to the cable that was removed from the battery. If there is a drain you will see it here. DO NOT keep the leads on like this for a long time as they do heat up and will melt. And this is to be done with car off with nothing on that you can control.

I'm leaning towards replacing the alternator, but want to be sure before dropping the $$. I'll put a DMM on it this afternoon when I get home. The only aftermarket stereo equip is the head unit. I would think if there was short or something the stereo would be acting up.

Before you get an alternator. Check your connections. Corroded cables can cause many issues. Pull the bolt out, and boot off the cables at the battery to honestly assess the cables. Green going into the cable is a sign of very bad corrosion.

Got the DMM out this evening. Got 14.4 volts at the alternator, 14.12 volts at the battery. Measured 15 mA drain at the battery with everything off. So everything is measuring good, so I don't know what the hell is going on. For whatever reason the battery dieing over night and ends up going bad. I had the battery charger/tender on all night last night. I expected the light on it this morning to be green indicating that the battery was fully charged but nope. Sat on the charger all night and never fully charged. This is really turning into a PITA.

penny in the ciggerate lighter...... idk.

sell it

I usually get everything from O'Reilly's. They've been good about warrantying out my batteries with no questions asked.

i thought my battery was dead yesturday but it was just the ground cable bolt was loose. i keep the 8mm wrench in my car just in case now.

Get the new battery, drive it home. Shut the car off. Restart it to make sure the battery has a good charge. Shut the car off. Disconnect the - terminal. When you get ready to go to work in the a.m., reconnect the - connection. If it starts fine, the problem's in your car. If it doesn't, O'Reilly might supplies batteries made in China. If it does start.......then what these guys are saying! lol.

The new battery will not give me any problems for 2-4 weeks. Then it starts going bad. The last one started to go south, so I take it and have it tested. It test good, then 3 days later I take it back and it test bad.

That is the plan for this afternoon. I talked to another guy at O'Reilly's that actually sounded like he knew what he was talking about and said to do the same thing. Take it off and bring it back to be tested inside.

I had an 85 Accord that used to eat alternators. When it ate the first one, I didn't have the money to buy a rebuilt one, so I bought a used one from the junkyard. Worked fine for a couple months, then bearings went out of it. So, I took it to a local auto electrical shop and they rebuilt it for me. ~$75. Lasted like 4 or 5 months. Brushes went out. So, by then, I had enough $$ to buy a rebuilt one from autozone for like $150 or $175 somewhere around where and it had a lifetime warranty. I went through like 4 of those over the course of a couple years. lol. But, they were all replaced for free. Then I got tired of changing alternators and getting stranded at any given time or place so I sold the car. If it's your alternator, I would say get a rebuilt one with a lifetime warranty due to my previous alternator troubles. Let us know what you find out!

Status Update:

New Alternator and Battery have been installed, as well as a new idler pulley bearing while I had the belt off. The old alternator tested good in the store, but I still decided to replace it. And I talked the guy into warrantying out the old battery for a new one, so I could start with fresh alternator and fresh battery. I should know in a week or so if the problem as been remedied.