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How to Test a Car Battery with a Multimeter

How to Test a Car Battery with a Multimeter


Hey guys ChrisFix here today I’m going to show you how to use a multimeter to test the battery on your car to see if it’s bad Some symptoms that you could have with a bad battery or a bad alternator Is that your battery light is on the dash the engines cranking slowly or not cranking at all there’s clicking when you turn the engine on But the engine doesn’t start so just clicks the battery seems weak or is it dead the interior lights or a [headlights] seem weak? And stuff like that these symptoms could be a bad battery or alternator this video right [now] is going to focus on the bad battery aspect of it to See the alternator tests watch my other video the link to that video is in the description below [one] of the first ways you could tell if your battery’s going bad is you put your key in the ignition you [turn] it to the run position and you can see Right there is the battery light That lets you know that the battery light is working most cars test the voltage of the battery through the battery light So if that blows out you won’t be able to tell if your [battery’s] bad or not and a lot of times I could trigger Another light like a check gauges light so what should happen is when you start the car. It’ll shut off if it shuts off Then your battery is good to test the battery what you want to do first is you [want] to turn the headlights on for about? two minutes this will get rid of any surface charge the battery may have as We wait what you want to do is you want to turn on your voltmeter and right now? I have [it] set to Ohms you want to set it to 20 volts or something above fifteen volts So 20 is what my voltmeter has and that’s ready to go two minutes later We’re going to shut the lights off and make our way over to the battery This is our positive lead, and this is our negative lead our negative is our ground now I’m going to connect our red to our red and our black to our black and you can see the voltage goes to twelve point eight five you want to have around twelve point six volts So this is good now Just because this is a good voltage doesn’t mean your battery’s good the battery could be holding a charge but doesn’t have the cold cranking Amps to start the car. That’s what we’re going to test [right] now So I’m going to go start the car with these attached and this shouldn’t drop below ten if this drops below ten then we have a battery problem You can see it dropped down, and then it popped back up, and now it’s at 14. That’s because the alternator is charging the battery Now you saw this drop down to about [ten] [ten] and a half and rose right back up, so that’s good This battery checks out has enough cranking amps and the cells are good and I knew this this battery is good I’m just showing you as a test of what should happen if this drops down below ten then your battery starting to go Below five your battery’s garbage You need a new battery cold cranking amps CCA is the measurement of how many amps a battery can deliver? at zero degrees Fahrenheit for 30 seconds and not drop below Seven point two [Volts] batteries are supposed to last about four years And that’s what most of them are warrantied to but only 30% of the batteries that are sold today reach that four year mark Now if you are having problems with your battery and this doesn’t solve it you also want to see to make sure your connections here Aren’t corroded you can see here There’s a little bit of corrosion But nothing bad what you might want to do is get some sandpaper some WD-40 [sand] it up if there’s corrosion on here You see like this blue green crystal and stuff you want to make sure you use goggles and gloves [plus] that stuff is corrosive it Could hurt your hands and it could hurt your eyes you can see that these terminals are actually pretty clean Obviously, I told you I had no problem with this car But let’s check out a battery at bad terminals that are dirty So here’s a good [example] of what I was talking about and if that happens you want to clean off [your] battery terminals Really good. So I have a piece of sandpaper, and that’ll do the trick. [you] just loosen this up Once you get all that dirt [and] everything out of here just sand the post down So you can see I clean the post off pretty good Clean the inside of this very good, so they attach Slide that back on [I’ll] tighten this completely with a ratchet [you] [know] the battery terminal is done as well that looks good So I’m going to tighten them up, and then we’ll take a reading now I know this battery is going to be low, but this will give you an idea of a bad battery Two volts that’s bad this battery is garbage. It’s six years old, and it can’t even hold the charge anymore I charged the battery last night to twelve point six volts and now it’s two volts I kept the terminals Disconnected to make sure there wasn’t any draw from the car So that’s an [example] of what a bad battery looks like one more thing after you done cleaning off the posts hit it with some WD-40 and That will prevent it from rusting and getting corroded again. So we’re going to look at one more battery. This is my truck battery this batterys [six] years old and you can see it’s perfect twelve point Seven volts So I ran the headlights for about two minutes now, we’re going to see what happens when we [started] up This [battery’s] running really [strong]. You saw it dropped down to 11 volts when I was starting it and The alternator is running well, and it’s going a fourteen point two five volts running that is excellent So you saw two good batteries and one bad battery the one bad battery won’t even be [able] to start a car These batteries that I showed you in this video are all maintenance-free batteries They don’t need any water if you have battery that needs water you’ll see they’ll have caps up here And you want to make sure that they’re not filled to the top of the cap But there are a quarter of an inch over the Electro the metal piece that’s inside there And if you need to fill it fill it with bottled water or distilled water so you don’t have any extra minerals or anything That’s in your water getting into the lead acid battery The other thing you should remember is that you could take your [car] to a major part store And they’ll test your battery for free. They have better equipment That’ll will thoroughly test this and you get a good idea How much life is left in your battery if this video was helpful give it a thumbs up also consider subscribing? I publish how to videos weekly and answer all the youtube comments and questions you guys leave and Watching these videos will teach you something new and hopefully save you some money and on the screen You’ll see different videos [that] have to do with the battery system Including [the] how to test the alternator video that video goes really well with this it’ll give you a good idea after you test your battery to go test your alternator and Finally check out the Chrisfix Facebook and Twitter pages with the links in [description] below

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100 thoughts on “How to Test a Car Battery with a Multimeter

  1. Very useful mate, always understood mechanics, never understood electrics. this was a massive help, off to test my battery!

  2. Great video, just like to add a couple of things;
    12V is the nominal voltage of a 12V battery, the actual normal voltage is 12.6V. When fully charged it should be in the range of 12.6 – 13.2V for a very good condition battery. If your battery is under 12V when fully charged it may be on the way out.
    I am a little sceptical of maintenance free batteries. They seem like a normal battery with easy access to checking electrolyte levels blocked off. When my Mazda 3 battery seemed bad, only 3 years old, I removed the panel covering these and found that the levels were very low. I topped up with distilled water and used a smart charger to resuscitate it. The battery lasted another 4 years, just gave it some TLC every 6 months or so.

  3. @t

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  4. Replaced a Hyundai Trajet battery after 12 years.
    Replaced a Citroen C5 battery after 5 years.
    Replaced a Ford Fiesta battery after 1 year and a week!

  5. Just skip all the bullshit about the car, and go to 1:11 to learn about the multimeter, where he failed to advise which of the three holes that the two red and black wires go in, and also fail to describe the dial setting well.

  6. Love the tip on spraying WD40 on the battery terminals to prevent rust and corrosion. Do those felt washers help at all? You can buy a kit of felt washers (one green and one red) plus some type of jelly to put on the terminals. At around $3 for the kit, WD40 is a lot cheaper to say the least. What type of multimeter to you suggest I buy? Thank you

  7. My cheap Harbor Freight meter 96308 only does 20a, 200a, 400a, 300v, 2000 ohm, 200kohm. I think I need to trash it and get a real meter.

  8. I have a 2013 Honda Accord sports. It takes several turns from the off position( never from ignition on) to start. Battery is good, alternator is good, I took the starter in to get it tested and it pass. What’s next?? Please help.

  9. That dude know nothing about cars the best way is to hold the horn and check if the sound of the horn is good or bad

  10. Hi Chris … I have watched many of your excellent training videos and passed them on to my son. We both agree that yours are the best in what is a pretty crowded field. Thank you very much from us both and I know from the comments many others feel this way. Quite an accomplishment .. congratulations!

  11. Dont put "bottled" water in battery. Only distilled or deionized. "Bottled" could be a million different versions of spring or tap water with minerals in it.

  12. I have a 2007 Nissan Murano and it has Nissan branded battery from 07-2016 it has a sticker 84 month limited warranty what would the dealership do give me a replacement? Autozone hooked up there scan tool and he said the battery is good the alternator is bad

  13. I did the test, my battery and alternator is good. My concern is that my dash cam read a lower voltage vs the multimeter, I used the cigarette plug in for power. Will a bad fuse or bad ground cause voltage drop?

  14. "Battery is garbage" wait wait wait please just don't change the battery before checking the coal in the alternator. Please consider changing the battery water and clean it out inside. Buy batteries with removeable caps..

  15. So if my truck battery is at 8volts while the truck is not on its no good? But then after i crank it twice it starts and it shoots up to 12volts.

  16. This video has issues. FIrst, you shouldn't disconnect the battery completely on many cars because it cuts power to the computer. I usually temporarily use a small 12V "scooter" battery with alligator clip wires when I need to disconnect the main car battery. Second, I wouldn't trust that Harbor Freight meter without first checking it against a much more reliable meter.

  17. I've learned a great deal. Thanks Chris. I'm just off outside now to test a battery that has been on trickle charge for 18 hours. Will let you know how I get on!

    UPDATE:- I ran the headlights for 2 minutes, then started it up. and ran at 14.39V. When I switched it off it showed at just over 13.6.

    I guess the key now will be how will it get on tomorrow after it's been left in the car.

  18. Ok, NAPA Legend battery, absolutely better data than a 3 year old (if it lives that long) Optima! WOW!!! 6 years old with that multimeter data, Just WOW!!!!

  19. Thanks Chris, I used this vid to diagnose a battery issue with my car. As always great info and precise. Also watched pretty much every video you have posted lol. Keep up the great work.

  20. disconnect the battery. open the cover of the cells. place multimeter negative (black wire) On negative post. take positive lead (red wire) and place metal testor in battery acid and check reading. when finished, wipe positive testor lead off with cloth before checking next opening on battery. The only correct way to confirm battery condition

  21. That depends on the response time of the voltmeter.

    Also it is advised to avoid putting the meter on amps instead of volts.

  22. tip, write the date on the battery with a sliver sharpie pen. that way you have a good working idea on how old your battery is.

  23. Chris – good video. Thx. Some bottled waters contain natural and added minerals. Only use distilled water

  24. I recommend you test your vehicle starting it at least 5 or more times – I use a Battery Tender to keep my car battery charged; The first time I started it it tested perfect but I noticed the voltage was lower; By the 5th time starting my car it barely turned over going down to 8 volts [or lower] during starting the car; So that means some of the cells are bad in my battery; My battery is about 5 years old; Time to get a new one. Thanks for your video.

  25. For a battery with corroded terminals, mix up a paste of water and baking soda.  With a tooth brush, brush the paste onto the terminals, scrubbing with the tooth brush until the terminals are clean.  Rinse off the paste with water.  I don't recommend sanding your terminals.

  26. Auto parts store tried to sell me a new battery and alternator, turns out the terminals were just loose.

  27. Actually the battery light comes on when the alternator is not putting out enough volts to keep the charge up on the battery. So the battery may be okay. Not unusual that an alternator before failing gives insufficient charge to the battery and you may need to replace both. A loose belt running the alternator can slip enough for the alternator not to put out sufficient power.
    In the old cars this belt ran just the alternator and you just adjusted it or if too stretched out replaced it. Today's cars use a serpentine belt and run various components and if the belt has stretched needs replacement. The serpentine belt uses a tension arm and roller/pulley and may loose tension as it gets older and need replacement. On many cars it is recommended to replace both the serpentine belt and tension arm together.

  28. Is wd-40 really safe like no harm to the battery or vehicle? Seen videos recommending to use backing soda mixed in warm water instead

  29. Thanks for the video..
    But I bought s multimeter like yours and not sure what to say the disl on to check the battery, and the fuses in the fuse box

  30. hey Chris. Following your recommendation I tested my battery… it is at 11.74 volts. Starting vehicle it drops to 11.55, no lights on or anything else. Are these numbers good? Just bought this battery a few months ago. Battery light came on yesterday while driving. Thanks.

  31. great video! thank you so much for sharing your knowledge. Knowledge is power but being considerate enough to freely share it is amazing. 🙂

  32. Really good, of course. I would add that one should NEVER attempt to run the engine without the battery in the circuit..do NOT disconnect it with the engine running! A weak cell or 2 in the battery (of course) can produce all sorts of apparent major systems malfunctions. Always start with a battery/alt. analysis. Continuing to use a really weak battery can permanently damage your expensive alternator. "Rebuilt" replacement alternators are often defective. So take care of the one you have.

  33. "Just because this is a good voltage doesn't mean your battery is good" You don't know how much I wanted to hear that lol. Car just decided not to crank but I know the battery had been getting weaker due to faulty alternator brushes (it would cause overcharge and undercharge). It still lasted a year after I replaced the brushes but now I think it's just dead. I'm still gonna try and charge it to see if the car can crank but I know it's now mandatory to replace it. It's currently at 13.5V.

  34. Has anyone had a driver's side seat run on the center console which causes the lid to not close straight on the console

  35. Awesome video. Straight to the point, no rambling, very informative. I'm subscribing and will continue to follow your vids. Thank you very much.

  36. The best explanation after i watched it very useful,please explain again about how to check fuse with multimeter,check sensor with multimeter

  37. Great video.
    You can make your battery last much longer by using an Optimate 3 or 4 battery charger / conditioner either when you are not using it, or at least 1x a month.
    I use it on all my vehicles and the battery LASTS !!

  38. I get a clicking when I first turn the key . It varies for how long . Then it will start turning over , once it engages I’m assuming , but it won’t start every time. It just keeps turning over . Sometimes Followed by starting , and sometimes not . It’s been doing this for a few days now and getting progressively worse .
    I bought a new starter . Before I put that in . Just wondering if anyone had any insight for me .
    Thanks much

  39. Hi I have a 97 achieva my battery is from 2013 and my alternator is from 2011 what been going on I been having a security light issue it start stall then start and be fine then I try it the next day or the following and it either start and stall or not just keep doing that intill I let it sit in the one position for ten or more mins for the light to stop and three time the car was dead it was clicking I had to hook it up to a battery charger and use that so she wouldn’t die while I get rid of the blinking security light but before I did that my battery ready was 11.50 not sure that a good or bad reading i don’t have a volt meter I used my thing. That fills up the tires it also has a feature that test the battery and alternator that was the reading I got then she started and then i checked the alternator and it spiked to 13.86 not sure if it’s my alternator or battery I know if you disconnect the positive cable while the car running if it stalls then it the alternator of it keeps running the alternator fine but I don’t want to chance messing anything up I’m not a mechanic and the car need other work and I’m doing one thing at a time and for a while it been sitting but I would run it every day or every other day or take it around the block I recently had my compressor replace and a new fuel tank pump put in new spark plugs new something else forgot what it called cause that car don’t use wires if you can please let me know what you think thanks

  40. This channel is the best Car DIY channel on youtube period. I wonder however how many average Americans have a multimeter at home.

  41. Battery life can also depend on the vehicle. I commonly get over six years out of the cheapest batteries in my 87 Isuzu Pup. Because it has no power equipment. At all. In my Mercedes W203 it's been harder to keep a battery working. I do use a BatteryMinder desulfating charger regularly which seems to make sure I get the full five years out of all of my batteries.

  42. Heh, just measured mine. After 2 mins, it is okay at 12,83 V stable, and 13,9 V after starting. But. During ignition, it drops down to 6,8 V and has a tough time starting sometimes – even the dashboard lights will struggle to appear. And once you turn on the rear and front fog lights, while running, it drops down to just 12,3 V. I guess it's time for a new battery.

  43. I'm actually having some issues with my car's battery (guessed that thanks to the video where you metioned what happens to my car btw), I bought a multimeter (finally, really needed one) and that saved it a visit to the mechanic.

  44. battery light has nothing to do with a good battery. It actually indicates if the alternator is working. When the voltage from the alternator goes above the battery voltage, the current can no longer flow through the dash light.

  45. dont use WD40, as its mostly for removal of rust or oxides moreover it is non conductive of electricity. Use CRC (contact redundancy check)spray for ultimate results….. bye bye….

  46. This was a awesome peace of information. People tend to ignore the battery maintenance and run into starting problems. This is a basic need for a driver and a owner to have a joyful drive. Thanks mate

  47. The proper way to test a battery is with a resistor and multimeter, but this looks like a great way to do it without buying something, having to do much, and just have a 10 dollar multimeter.

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