Wrench Wench has been in love with automotive mechanics for decades. She loves sharing advice with fellow DIY mechs and curious cats.
The typical battery, in vehicles made in 1952 and later, is a “wet-cell” battery—a plastic cube containing sulfuric acid and lead, with two terminals coming out of the top or the side. This short guide should be reliable unless you have an aftermarket battery with special needs, such as a dry-cell battery, or a hybrid like a Prius.
In my years as a mechanic, one thing I have learned is that an old battery or loose battery cables can cause really big problems that make it appear that something complicated is wrong with your vehicle. Even experienced mechanics and DIYers are sometimes stumped by a simple problem with a battery past its prime until they realize they've ruled out all other potential problems (and then some). That's one of those "d’oh!" moments when you realize you could have saved yourself an hour of diagnostic and repair time just by checking the battery and its cables.
Your vehicle’s battery is like its heart: Without it, your vehicle doesn't have the power to start, move, or do anything else. So it's important to understand at least a little bit about your battery and to know the most common signs that it needs to be replaced.
Signs Your Car Battery's Dead or About to Die
- Your engine cranks, but it doesn't start.
- Your engine doesn't crank or start, and the lights don't come on!
- One day it starts fine, then the next day it won't start at all.
- Cold cranking is hard work.
- You've jumped it a lot already.
Each of these scenarios will be thoroughly discussed below.
1. Engine Cranks, but Doesn’t Start
If your engine cranks or turns over when you turn the key, but it won't start, I say the most likely culprit is your battery. It might be your starter, it might be something else, but 94% of the time, it's really your battery, even if the car is cranking fairly vigorously. Even if an ammeter (current-measuring device) says the battery is good, it can still be a few volts shy of what your vehicle needs to run efficiently.
When you find yourself with a car that won't crank hard enough to start, you'll want to use jumper cables or a jump-starter box to get it running again.
Once your car is running again, disconnect the cable, then let your engine run for 30 minutes so that your alternator can charge up your battery again.
After that half-hour, when you are stopped at home or in a safe place, do a little test. After you turn the engine off, wait at least a minute, then start it again. Wait another minute and start it another time or two to make sure that you won't be stranded at the gas station or wherever you go next.
Note: At this point, most batteries will have charged themselves up from the running of the alternator and be fine for a day or two. Do not take that time for granted. Use it to hunt down a new battery and replace the old one before you end up stuck in the middle of nowhere.
2. No Crank, No Start, No Lights
This situation is pretty straightforward to diagnose, and it's an even stronger indication that your battery is at fault. Your battery powers all the accessories and lights in your car, especially when the alternator is not running. So, if your car just seems to be completely void of all signs of life, then your battery is the first thing you should be looking at.
And be aware that in this situation, where your vehicle doesn't even have the juice to work the lights or turn over the engine, it could be a combination problem involving your alternator as well.
If the car won’t crank or start but the headlights do work, that may indicate a more interesting problem, maybe the starter or a mechanical problem in the engine.
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3. One Day It Starts Fine, the Next Day It Won't
If starting is an intermittent problem for you, it's a sign that either your battery terminals are loose, broken, corroded, or calcified or that you have a parasitic draw (your power is being drained by some gizmo that's on when it's supposed to be off, or by some wire that’s touching something it shouldn’t).
- Check out the battery cables first, as they are usually the prime suspect and are easier to check yourself.
- Make sure the cables fit firmly and securely on the battery posts. There should be zero play in them. You shouldn't be able to wiggle them even an inch when they are tight. Also, make sure that the cables going to the terminals are not frayed or falling apart; if they are, replace them as soon as possible.
In this video, Eric the Car Guy shows you loose and corroded cables, and how they can cause a drop in power to the starter.
Parasitic draws from sources other than the battery cables are fairly common. Suspect a parasitic draw if the car starts right up if you drive it several days in a row, but then fails to start if you let it sit for a day. To investigate parasitic draw issues, see your favorite mechanic, or look at the last section of this article, and get ready to have fun with an ammeter or voltmeter, as these are the tools you'll need to check your alternator, accessory lights, fuses, radio, alarm, and all other components that might be draining your battery in secret.
4. Cold Cranking Is Hard Work
If you look at your battery, somewhere on it you should find a label stating a number for "Cold Cranking Amps.” Those amps are responsible for giving your engine enough energy to get started the first time of the day, generally referred to as "cold cranking.”
Thus it’s not surprising that an early sign that your battery is running out of life—a sign most people miss—is that you are regularly putting extra energy into starting the vehicle. You know what I'm talking about. You get in your car, you tap the gas pedal, you turn the key a few times, and all you get for the first few minutes is lots of weak rotations of the engine. After you’ve all but decided the car is going to make you late for work, it suddenly starts up and sustains an idle.
Now, what I mean by "regularly" is having to do this more than three times per week. That would be a sign that your battery is giving notice and getting ready to retire.
But, keep in mind that if it’s really cold out, it’s fairly normal for your vehicle to hang back and start only with difficulty. Not only is gas hard to vaporize and oil gooey when it’s cold, but batteries put out only half their normal power when the temperature is 0˚F (and only a third of their power when it's 32˚F). So in the cold, you may have to be patient. But, if your car doesn’t go back to a reliable “cold” crank when the weather warms up, you’ll want to get a new battery within the next three months.
One more possibility worth noting is that your battery was never big enough for your vehicle in the first place. Even a well-seasoned mechanic has gotten the wrong battery for a specific vehicle, causing a wild-goose-chase investigation of a mysterious starting problem. Make sure you look up your car online or ask in an auto parts store to find out what level of Cold Cranking Amps (CCA) and voltage your car needs to start and run properly.
5. You've Jumped It a Lot Already
I have a simple hard-and-fast rule that I follow when it comes to having to jump your battery. No matter what reason you had to do it—the battery was old, or maybe the starter, fuel pump, or alternator were bad, or maybe you left your headlights on or your door ajar all night, or you ran out of gas—the rule is this:
Even a fairly new battery can turn into a dud really quickly if it has been jumped more than three times in a week. Using a jump box or jumper cables is hard on your battery. They work by figuratively "shocking" it back to life.
Now, you might think I'm crazy about replacing the battery after such a low jump count, but hear me out. One of the most common things I see happening in relation to vehicle battery problems is that the driver or mechanic will assume that because the battery wasn't old, or wasn't the specific culprit for the battery draining itself, they don’t need to expend time or money getting a new one. Then, when they try this and that to diagnose the problem, they keep jumping the battery until, finally, the alternator and starter go bad, leaving you with a need for a new alternator, starter, and battery.
Save yourself the headache and just replace the battery if you've had to jump it more than three times in a week. You won't regret it.
Signs of a Dying Battery
|Pre-Startup||During Startup||While Driving|
No lights, guages, dash lights or electrical come on upon turning the key in any direction.
Turns over 3 times or more before starting.
Mildly rough Idle during traffic stops.
Battery needs to be jumped every 3–5 days or more.
Lights andor Accessories dim with each turn over before starting.
Radio andor other accessories shut off intermittently.
Battery dies within 15–30 mins of sitting with engine off & radio/accessories running.
Tougher time starting after sitting for long periods, especially in colder weather.
Accessories belt squeals while driving up hills or while hauling.
Starter andor Alternator have died & been replaced already.
Accessories belt squeals briefly during or after startup.
Lights andor Accessories dim or blink when accelerator is pressed.
How to Jump-Start Your Car Battery in 10 Easy Steps
- Park a car with a functioning battery so its front is as close to your car's front (pointing toward one another). Leave at least 18 inches of space between and never let the cars touch.
- For manual transmissions, place the car in neutral. For automatic transmissions, place car in park. Turn off engines, remove keys, and set the parking brake on each car.
- Get out your jumper cables. Make sure none of the metal clamps touch one another. Notice that each set of clamps has one red clamp and one black clamp.
- Open both car hoods. Locate the batteries and battery terminals. Terminals are usually covered in red or black, with a + or – sign on top. Make sure that you can identify which is positive and which is negative.
- Attach the red cable clamp to the positive (+) battery terminal of the dead battery. Make sure there is a solid connection to terminal.
- Next, attach the other red cable clamp to the functioning vehicle’s positive (+) battery terminal.
- Now, connect the black cable clamp to the working battery’s negative (-) battery terminal.
- Do not connect the final black cable clamp to the dead battery. Instead, attach that clamp to an unpainted, metal part of the car, such as a clean nut on the engine block. This will help ensure a safe jump.
- Start the functioning car's engine. Wait a minute or two and try starting the car with the dead battery. Sometimes it helps to rev the functioning car's engine a bit. Once both cars are started, leave them running for a few minutes.
- To disconnect the jumper cables, start with the black cable clamps. Do not let them touch while any part of the cables is still attached to a car.
How Long Does a Battery Last?
- Batteries normally have a maximum life expectancy of two or three years, even if manufacturers say they will last five years or more. If anyone sells you a “super long life” model, keep your receipt and get a warranty. Especially if you use your battery for a lot of accessories (things other than starting your car) it’s unlikely to last as long as promised.
- Optimally, you should replace your battery every two and a half years or so—before you have problems.
- Other things can affect its lifespan, since a battery relies on other parts to do what it does. It needs help from your alternator, your starter, the solenoid, the battery terminals (which need to be clean and free from corrosion), and its own cables (which need to be intact). Though as I argue below, the problem is very often just age, I’ll admit it can be something else.
- The age of a battery, even if it doesn't show any obvious signs of being old, can affect your vehicle in negative ways that will slowly add up to a big repair bill. That’s why I recommend replacing it before you have problems with it.
- Your ordinary battery doesn't do so well in extremely cold weather, which may be why you have to pump the gas, or turn the key back to prime the fuel pump, or do a little dance to get the truck or car started on chilly mornings.
How to Diagnose a Parasitic Draw
Because so many battery issues are caused by a parasitic draw that is slowly draining it dead, I thought you might like to see some videos that can help you finally kill that parasite!
Method 1: Use a Multimeter
As in the videos below, the fastest and most efficient way of finding your parasitic draw is to use a multimeter. Even the most inexperienced diagnostician can do this test in minutes to find out if you have a draw. Just make sure the vehicle is off, the car's negative battery terminal is disconnected, and the car doors are shut and other accessories turned off. Set your multimeter to 10 amps DC, touch the positive lead to your disconnected negative battery cable, and touch the ground lead to your negative battery post. If your meter shows anything above 50 milliamps, you have a parasitic draw. Watch the first video below to find out how to identify the fuse or relay that is eating away your battery, plus some possible quick fixes.
Method 2: Use a Fuse Checker
On a pre-1985 vehicle, you can use a small probe called a fuse checker to look for draws. It's not as accurate as a multimeter, but will work just as well at finding out what is still on when your car is supposed to be off. This method can also work on newer vehicles if you don't have access to a multimeter. To use this method, simply make sure that the car is off, the door pins are all held down in the "closed" position, and your negative battery cable is disconnected.
Best Car Batteries
Odyssey PC680 Battery
This battery is famous for its excellent efficiency. With a strong and rugged construction, this battery has a the ability to tolerate a strong pounding regardless of the environment.
XS Power D6500 Battery
This battery features a sealed AGM. It is ideal for 3000-4000W car audio sound systems. It is a leak-proof battery with no external vents. This design allows the battery to fit almost factory battery locations without any hazardous leaks.
VMAX857 AGM Battery
With this battery, you can experience excellent functions like heavy duty grids, SLA, and AGM technology, vibration and shock resistant. The VMAX857 is also a non-spillable and non-hazardous battery.
Optima 34/78 RedTop
The RedTop battery is designed to deliver the most energetic 5-second starting burst of all. Its lifespan is twice that of conventional lead-acid batteries.
Optima D35 YellowTop Battery
This is a small car battery with excellent performance. This battery is designed to provide deep-cycling capability and extra performance to meet your vehicle needs (if your car has a lot of extra accessories).
How Many Miles Should a Car Battery Last?
A battery lasts about four years on average, but mileage varies wildly from driver to driver. One thing is for certain, batteries don't last forever. There are many different factors that could lead to the demise of your car battery. It's not always such a simple thing to diagnose.
Factors That Determine a Car Battery's Lifespan:
- Where you live
- How you drive
- The condition of your charging system
- How you use your car's accessories
When Should I Replace My Car Battery?
After three years, it's normally time to install a replacement battery. On average, after four or five years, most car batteries will be almost completely unreliable. In fact, many old car batteries can present a number of safety issues.
What Is the Normal Charge for a Car Battery?
Fully batteries should measure at 12.6 volts or above. However, when the engine is running, this charge should measure at 13.7 to 14.7 volts. That said, if you don't have a multimeter to tell you the voltage of your car's battery, then you can do a test of your electrical system. You do this by starting the car and turning on the headlights.
What Percent Should a Car Battery Be at?
Car batteries can vary from car to car, depending on the scale of the automobile. That said, on average, automotive lead-acid batteries should be maintained at a 75% charge level or higher for their best performance.
Does Draining a Car Battery Damage It?
When a car battery has been drained below a state of full discharge, all you can do is check the electrolyte and put it on a trickle charger. It's also hard on an alternator when you drain a battery, because they aren't designed to charge batteries from a state of full discharge.
I Have a New Battery That Is Fully Charged. Why Can't I Start My Car?
If your vehicle won't start, it's usually because of a dying or dead battery, loose or corroded connection cables, a bad alternator, or due to an issue with the starter. It can be hard to determine if you're dealing with a battery or an alternator problem.
How Do You Know If It's the Alternator or the Battery?
The answer to this question varies from situation to situation, but I'll address a common one here. If you jump start it and your engine starts running, but the car will not start again once you turn it off, then the battery is likely the problem. While, in this case, the alternator is doing its job of keeping the battery going once it has been jumped, the battery still can't hold a charge when the alternator is shut off. Again, this is a sign that the battery is the culprit.
Where Can I Bring My Old Car Battery?
Battery Recycling is very important. If you have an old car battery lying around, bring it in to AutoZone or other shop for recycling. Some of these auto shops will give you a $5 merchandise card for turning in your old battery. Remember to check the stores' sites for restrictions and further details.
What Do I Do With My Old Car Battery?
You should take the battery to an auto shop or parts store. In fact, the most common way to recycle a car battery is to take it to your local auto shop or auto parts store, where car batteries are sold. You must recycle your battery appropriately. Car batteries, both lead-acid batteries and nickel-metal hydride (NiMH) batteries, eventually wear down and need replacing. However, getting rid of an old car battery once you get a new one isn’t as simple as just throwing the old one away in the trash. Because of the environmental health consequences, throwing a car battery in a dumpster could subject you to serious fines or penalties.
How to Recycle a Car Battery
- Finding recycling location. Use an online search engine to find locations near you that accept car batteries for recycling.
- Confirm that they take car batteries. Call ahead to confirm they accept car batteries before bringing it in.
- Secure the battery in your vehicle. Place the battery in your vehicle’s trunk, hatch, or on the floor on a safe, disposable item (just in case of any leakage)
—use a section of plywood, a heavy plastic lid, or a metal item like a garbage can lid. Make sure the item you choose doesn’t slide around. You'll want to prevent the heavy battery from damaging your car or other items around it.
- Check in with attendant. After arriving at the battery recycling depot, check in with the attendant on duty. Make sure to inform them that you wish to dispose of a car battery.
- Have your battery recycled. Have the attendant safely remove the old car battery from the back of your vehicle.
Thank you to everyone who has been so wonderful and left so many great comments and questions. Please, if you need more immediate information or advice and you aren't able to check in with your mechanic, feel free to email me directly at Acceleratedauto@gmail.com
Your questions will get answered and possibly featured in a new article!
Learn As You Go
This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.
© 2012 Wrench Wench