Help understanding a battery test

My car (97 Camry) would not start yesterday and made a clicking noise when I turned the key; AAA came and tested the battery. The results were as follows:

Battery Test
Bad Cell–Replace

Starter Test
Jump Started

Charging System Test:
No Problems

Drain Test:
0.08A, Pass

The technician jump started the car and got it running again. Despite the fact that the test says, in bold capital letters “Bad Cell–Replace”, the technician said I could try to keep driving it and cross my fingers. Is it safe to keep driving the car–obviously I am running the risk that I will be out somewhere and the car won’t start, but could something bad happen while I’m driving on the highway, for example? The car did start just fine this morning and the battery light on the dash is not lit. My uncle (who bought the current battery about 6 months ago) is convinced that I must have left the lights on or something–I’m pretty sure I didn’t, but I don’t want to replace the battery unnecessarily. I do not drive the car very often (once or twice a week); it has only 40,000 miles on it.

A 6 month old battery is still under warranty. Bring it to the place of purchase and have them test it and hopefully replace it at little or no cost.

Bring your AAA analysis with you.

That is a great idea; unfortunately the battery was bought out of state and I’m not sure if we are in possession of the receipt. I will try giving them a call in any case though.

If the test really showed a bad cell (could be true – batteries do sometimes fail young), then I think continuing to drive on it is a bad idea, especially with winter weather coming. You risk getting stuck somewhere cold and inconvenient.

I think you can get a free test at the big chain parts houses or maybe at Sears.

Current battery was purchased out of state – sometimes you can find a local vendor to honor the manufacturer’s warranty.

Can’t find the receipt? Oops. I guess some of us are more retentive than others. When I did Dad’s estate a couple of years ago I found the original bill of sale for his 1948 Studebaker.

If the battery was purchased at a national chain they might be able to find it in their computer (if your uncle asked them). But at that point, it’s probably not worth the hassle.

One of your questions was whether something bad might happen when you are out on the highway. That is highly unlikely. The more likely scenario is a repeat of what you already experienced.

The only highway mishap I can think of would be if the cell failure was of a nature that caused excessive gassing that the battery vent could not handle, leading to popping the top off the battery. Such a failure mode is unlikely on a six-month-old battery, even assuming recycled materials.

Forget the receipt, there should be the little popped bubbles on it indicating a date. If you bought it at a big box store (Wal-Mart, Sears, Advanced Auto, AutoZone, etc), they should all exchange it. If it’s the same make as those stores, even, one of them will exchange it for you.

I believe those bubbles are busted when the battery is shipped from the manufacturer, so at worst it should only indicate total age. It’s possible it’s over a year, but you should get some kind of credit for it, anyway.

If none of the bubbles have been popped, then you’re in luck, pop last months and go for it.

Thanks for the help. Just to defend my honor, I would have kept the receipt, it got misplaced somewhere in between my uncle and my wife…I won’t name any names…

I will check it out tomorrow, call the company, and see what I can do in terms of exchange.

So I spoke to the company (Battery Warehouse); the guy there said that the “Bad Cell” result could come from the car sitting too much, and that it’s possible the battery just needs to be charged; he recommended I get the battery charged overnight at 10A. He said the alternator would not be enough to bring the battery up to full charge without a lot of driving. However, when I called Meineke, they said to just run the car for 15-20 minutes and that would probably be sufficient. Who is right? Or are they both right?

It can take several hours to thoroughly charge a car battery.
Lead-acid batteries can’t be rushed.

Get yourself a small automatic battery charger ~5 amps, “Battery Tender” or similar.
Charge the battery overnight every 2 months.
That’s what I do. I also drive 2-3 times a week, mostly short trips.

Lots of good info about battery care here:

Better to use a battery charger.

A car’s charging system is specifically designed to bring a battery up to normal charge, and to do so quickly. Driving for 15-20 minutes will do the job, and an hour of charging at 10A also is all you need.

And you don’t really need a full charge at all times. Assuming your car’s starting system is working properly, you only need enough of a charge to ensure a start each time. Then even a short drive can replenish the charge. Of course, frigid winter temperatures add another complication.

This advice assumes you have a battery in good condition. We don’t know for sure if your battery is sound or not. If you suspect the battery at all, don’t bother with constant charging. Just have it replaced.

A car’s charging system is specifically designed to maintain a full or very nearly full battery, and deliver a constant system voltage.
It is chemically impossible to thoroughly charge a lead acid battery in 15-20 minutes, unless it’s already over 95% full.
A lead-acid battery that’s chronically undercharged will lead a short, unhappy life and die of sulfation.
There’s tons of literature out there to back up what I am saying.

It’s quite possible that the battery sat on the shelf for so long that it began to sulfate before it was purchased. That’s why when a battery is purchased you should look at the date code on the battery to determine it’s date of manufacture. If you don’t know how to read the date code on a battery, then ask for a battery from the back of the battery storage rack as these are the newer batteries, and the batteries at the front of the rack are the older batteries.

The tech from AAA probably used a conductance battery tester. This type of battery tester is capable of testing a discharged battery without recharging the battery. And it’s capable of detecting a bad cell within the battery. If the conductance battery tester indicated a bad cell, I’d believe it.


Update: The car drove around for a while, then wouldn’t start again. I got jumped by AAA again, took it to Meineke, who said the alternator is dead and the battery has shorted out. To replace both alternator and battery he will charge $433. Does this seem right and fair?

Thanks for your help. I know this is a “call your dad” issue, but my dad’s a Manhattanite, so he’s no help…

Meineke? RUN AWAY. You had a reasonable diagnosis that explained what the problem was. Just get the battery replaced (I’d buy one from Walmart) and then take it to a reputable shop and have the charging system checked out.

Also, Toyotas can have a bad starter solenoid that acts like a weak battery. But the symptoms are a bit different: a ‘click’ when you turn the key, no start, but try it several times and it might start, meanwhile all the accessories work fine (headlights, radio, fan, etc.).

A dead or low battery can put extra strain on the alternator. Another reason you want a good battery, fully charged, using a real battery charger.

Why do you think Meineke can’t be trusted? What would provide evidence that the alternator is indeed broken? And if I am going to run away, how do I do so if my battery is dead? :slight_smile:

I’ve had bad luck with chain shops like Meineke. But you’re right, if it’s immobile, then I guess you will have to have them put in a battery. But do not have them put in an alternator, a charged-up battery will run your car fine for plenty long enough to get it to a good independent shop. You can find one under the ‘mechanics files’ link at the top of this page.

Why don’t you ask Meineke to tell you exactly what is wrong with your alternator? Get it in writing and post it here. Doesn’t charge the battery may be all that you can get. $433 sounds pretty close. That kind of money makes some learn how to install a rebuilt, not normally a difficult task.

As was mentioned, a bad battery can cause your alternator to overwork and eventually cause it to fail.

Not sure why this is such a big discussion. Its pretty simple. Your battery has a bad cell. Thats not going to come back. Replace the battery. By driving with a bad battery yes you are putting more strain on your alternator. But no I would not put a new alternator in it just yet. It depends on how the alt is really being tested. I bet if the alt were to be bench tested it would be fine. And for the record…making a 15 to 20 min drive twice a week is killer for batteries. It will not recharge your battery correctly and the life of your battery will be greatly reduced. A 10A battery charger is not an over night charger. You need a smaller trickle charger, 2 or 5A.

By you waiting so long to buy a different battery and trying to “save money” and get it replaced for free…you are hurting your charging system. A charging system is made to do what it says…but that is with a good battery. Dont over work your system. You will end up paying more in the end. Just buy a new battery…what is it like 60 bucks???