How do you tell if your car battery needs to be replaced?

Last week, I noticed it was taking an extra turn or two to turn over my car in the morning. Like an idiot, I ignored this.

Then this morning, after sitting unused all weekend, it wouldn’t turn over at all, although the lights and radio worked fine. I hooked up one of those portable jump starters, that I got for Xmas a few years ago, and it started immediately. Woo! So I drive the 25 minutes to work, and hope it was a one-time thing. Maybe I left a light on or something.

No such luck. It didn’t start after work either. I jumped it again and got home and now I have a problem to solve.

Any ideas? Should I replace the battery as a first step? It’s at least a few years old.

I had very similar symptoms when my car battery died.

You need to replace it. It will only cost $50 or so and you can drop it in yourself in under 15 minutes.

You will not be given significant notice of a fading battery because of changes in design. Back in the70’s batteries were larger and less powerful. A low-end battery made 350 cold cranking amps. Today a low-end battery makes 650 cold cranking amps and is smaller in size than the 350 CCA cheapie. The difference is an increase in the number of plates and a subsequent decrease in the space between them. Instead of a slow decline in performance you are more likely to experience total failure. This is due the reduced spacing and the tendency to short out a bunch of plates at once. It is common to kill a battery in mid-start because of the amperage a starter uses.

If you have a stick shift and know how to start a car by rolling it and popping the clutch then you can tell if the battery is DOA by turning on the radio to an AM station. Batteries act as a noise filter and when they completely die you will hear a static whine from the alternator.

With that said, most batteries last between 4 and 5 years.

Start by cleaning the battery posts and cable ends. If that doesn’t work, replace the battery.

If the battery cannot hold a charge, it’s time to replace it. If it’s a completely sealed battery where you cannot check the fluid levels (most batteries nowadays), then you should bite the bullet and replace it. Here’s what you should do: check the voltage after a long drive, and make sure that it’s 12+ volts. Then check the voltage again, say, 8 hours later. If there’s a big drop in voltage, the battery’s gotta go. You might want to also check that it’s not a loose alternator belt that is causing your battery not to charge correctly.

It is possible that it may be some other cause that your battery is not functioning properly.

First, as stated before, check your cables to rule out corrosion.

Second: Check the belts that run the alternator. They should be tight enough to make the alternator turn enough to charge the battery.

Third: Check out the charging mechanism. It must work in order for the battery to recharge after a start.

If it were me, I would take it to an Auto Electric shop or to Sears and have them check out the charging system, belts and the battery to determine what is the cause. If you just replace the battery, you may have the same existing problem causing the battery to fail.

Yeah, careful if the battery won’t hold a charge. It could be because I’m a klutz with cars, but the other month I had a weird incident with my car battery.

The battery in my 3 year old car died for no reason I could think of. So I jumped it with another car’s battery. Turned it off after a few seconds, then tried to start the car by itself. No good. Jumped it again, and let it run for about 2 minutes this time. Turned it off, and then when I tried to turn it on under its own power again, BANG! Car battery exploded. And I mean exploded, as pieces came off and blew the battery cover clean off. Sounded just like a gunshot going off in the hood (get it? BUWAHAHHAA-----man, I’m witty). So yeah, might’ve been just me, but the next time the battery died and wouldn’t hold a charge, I said screw it and had it towed to get the battery changed under warranty.

I’m guessing you don’t have warranty on a car a few years old anymore, but I personally won’t mess with another battery that won’t hold a charge in less than a few minutes span.

Thanks all!

Another tidbit of info I forgot to mention… once I had driven home and was safely in my parking space, I checked to see whether it would turn over. It did, which seems to imply it charged at least a bit on the way home, and that it had a charge when I left it.

So in the morning I’ll check the voltage with a multimeter and see what I get. I figure it’ll be low and won’t start, in which case it lost the charge overnight and I can blame the battery. (Or some random electrical drain, but that’s a much more complicated proposition.) And I’ll check the belts, since it might be slipping and not charging fast enough.

Oh, and is there anything I should watch out for to avoid killing myself with the multimeter? I’ve only used it on non-deadly circuits before.

Yeah, don’t stick a pointy lead into your carotid artery. :smiley:

Automotive 12 volt systems are non-deadly. It would be easier to fry the meter (and that would take some effort) than to injure yourself.

If you want to eliminate the possibility of a drain, disconnect the battery tonight.

      • Around where I live, the Auto-Zone parts stores (a big discount chain) will automatically test car batteries for you. All you have to do is bring the battery in and wait a few minutes, they don’t even charge for it. Call around to places near you and ask if any offer this service.
  • Also (as usual) jump-starting a car at all is bad. If your battery suddenly goes dead for no obvious reason then it is best to get it tested and trickle-charged unless you are in an emergency situation. Jump-starting a car can damage the alternators and batteries in both cars. Alternators come with instructions that warn you not to jump-start them on a dead battery, and batteries have instructions that warn about exceeding their rated current draws. Hooking ANY dead battery up to a car’s running electrical system will do both these things.
  • Also use a multimeter and test the current draw when the car is completely turned off and the battery contacts are connected in, it shouldn’t draw more than a few milliamps of current. Then test the voltage while someone revs the engine, it should go up to around 14 volts. Assuming you can get the car to start, that is. If the current is a couple dozen milliamps or more, or the voltage won’t rise above 13 volts or so, something else is wrong that needs to be fixed, and charging the battery and jump-starting a million times won’t fix it.

Where did you make the connections with the jumper cables? Were they completely secure? You should never, ever make both connections to the battery and should always make the last connection made/first broken well away from the battery. You are damn fortunate it happened the way it did as battery explosions are commonly while breaking a juper cable connectio which means sulfuric acid exploding in your face. When I worked at Biosphere 2 one of the electricians pointed out something in the ceiling of an aux generator room. A truck battery embedded there after it exploded when someone improperly jumped the generator with a golf cart.

Mine died suddenly one night a while ago. I had to call a guy to come and replace it. He checked it first and pronounced it dead. We chatted while he was doing his stuff and he said that nowadays the average battery lasts about 3 and a half years. I kind of expected better but since he fits 150 a week I guess he’d know.

I managed to replace it today. While it was way too humid to do any work outside, it wasn’t that tricky. Messy though. The hardest part was getting the plastic shield around the (+) terminal out of the way, which involved 4 tiny plastic clips, one of which was on the bottom out of sight.

I must say, the old one lasted quite long. I assume it was the original from 1998 since no one in the US would use a Panasonic brand battery.

don’t ask, what kind of guy did you call who came out and fixed it? That seems like it would be a worthwhile trade-off to avoid the nastiness.

Mine’s nearly five years old, and has outlasted both the original starter and the original alternator. Does it make sense to preventatively replace a battery?

Charging a wet cell battery such as those in your automobile is potentially very dangerous - particularly so in an unventilated area. Under charge, a wet cell battery generates hydrogen gas.

The battery in my Mazda truck died after only 2 1/2 years (36954 miles). I had left work and it worked fine. Ran into Kroger for 2 minutes and it died while I was in there and it wouldn’t turn over or click or anything when I put the key in and attempted to crank it when I came back out. No warning whatsoever.

I think I rang Marshall Batteries. As far as I know they are a national chain. Their slogan is “Holler fo a Marshall” and they deliver and fit batteries 24 hours a day. Surely there are similar services everywhere. Marshalls have been in business here since 1935.

I have a 2001 Honda Civic. A few months ago, I noticed it was cranking slower than when the car was new. I figured, yeah, 36 to 48 months. I simply waited for a sale at the auto parts store and replaced the battery. Problem solved.

The best way to avoid trouble is to replace the damn things after 3 or 4 years whether they need it or not.