Skip to Main Content
Auto Repair Blog

Published 07:00 AM, Tue March 22, 2016

View Comments

WHY WON’T MY CAR BATTERY HOLD A CHARGE?

Knowing how to jumpstart a car battery is a good skill to have—but what happens when it’s not enough? Most of the time when your car won’t start, you assume it’s because there is a problem with the battery. You pull out the jumper cables, jump start it and go on your way. But what if the very same problem occurs the next time you get in the car?

This simply means that your car battery isn’t holding a charge. But why? There are several different causes that could be behind your run-down battery.

The Causes of a Failed Charge

Here’s a quick rundown of some of the most common causes of a battery that won’t hold a charge:

  • You’ve left your lights on, or some other accessory that draws battery power even when your car isn’t running.
  • When you drive the car, the battery isn’t getting recharged, i.e., there is a mechanical charging problem.
  • There is a parasitic electrical drain on the battery, possibly caused by a bad alternator.
  • The battery is simply old and it’s time for you to replace it.

Diagnosing the Problem

While there are multiple causes of a failed charge, you might be wondering how to determine exactly which one is to blame. Perform the following tests to find out:

  • The first thing to do is try to turn on your headlights. If they come on with their normal brightness, your problem is probably a bad starter or poor wiring—not the battery. If the lights do not come on at all, or if they’re dimmer than normal, then the problem is more likely with the battery.
  • To test the voltage of your battery, get a voltmeter and connect the red lead to the positive terminal, the black lead to the negative terminal. Hopefully, you’ll get a reading of over 12.6 volts, showing a fully charged battery—but if not, there’s definitely an issue with the battery being poorly charged.
  • At some point, you’ll want to ask yourself about the condition of the battery itself. Does it look obviously corroded or worn out? Is it more than four years old? If so, then the simplest solution may be to have the battery replaced.
  • Something else to consider is that the problem is your alternator. If you detect cracking or fraying in the alternator cables, that’s an obvious sign that something’s off. And if you jump start the car only for the battery to quickly lose its charge and the engine to stall, that’s suggestive of an alternator issue.

Even if you do believe you’ve discovered the exact problem, you’ll probably want to get an expert opinion. Buying a new battery when the alternator is the real problem—or vice versa—will prove highly frustrating when you end up spending more money than necessary. Bring your car to a local car care center for an inspection so you can get to the bottom of what’s truly causing your lost charge.

 



  • Kevin Watkins

    My car battery died the other day. I jumped it, drove it around, and then the next time I went to start the car, the battery was dead again! Jumped it, drove it, parked it, dead. I took it to my guys at BND Auto Repair (www.bndautorepair.com) and it turns out, I just need a new battery. Go figure. Just bought the car (used) a few months ago so I’m sure it was just its time.

    • Farhad Mirza

      i tried the same steps you described, my question is by any chance if you jump start the car and car stays on, but turn it off then the battery fails to power a start, cant be alternator but just bad batt?

      • Joseph Jackson

        Yes

  • Shell Smith-Thomas

    I’ve changed the battery, terminals and the alternator and battery still isn’t holding charge. Any suggestions?

    • David Hamilton

      bad battery

    • Sean M Brown

      Check your ignition switch, or starter relay

  • Arsam Sarabi

    my battery is new but flat out (drove me 40 miles). I changed the Alternator. but still wont hold charge in the battery even after jump starting it and leaving it running for a while. it works a little bit after disconnecting the cables but then dies again. any ideas?

    • Glenn Campbell

      The place you bought your new battery from will do a free charge test. This is to prove that their new battery is, indeed, new, and if the car isn’t charging it, you might think it’s their battery that’s faulty. The free test will tell you what to do.

  • Mandy Dobarro

    My Chevy Venture 2004 won’t stay charged. I have to use a battery charger/jump every time I go to start it. Even if I drive for 20 minutes the minute I turn off the car-no power. I have to re-jump to start. Today though It did not work and I had to get a jump from a Jeep(took a few tries too). I have been to many many mechanics and specialists and no one has a clue. I just changed the battery less then 6 m ago. Everyone says the alt and trans are okay. I have put it on several machines at said specialists(At $100 a pop) and they have no clue, but I’ve been told for $700-$1000 they will “search” for the problem. I don’t have anymore to spend now and no idea what to do. If I could figure out what was wrong I could go from there. One mechanic told said it was definitely the radio draining the battery and offered to remove it for me. I refused and took my broken van home. I have no idea what I am going to do and my savings are depleted.

    • Glenn Campbell

      by refusing to remove the radio, what you’re saying is that you’d rather have a broken car with a radio than a fixed car with no radio, My sound system uncouples easily, because with any electrical issue that’s the first thing to haul out. Your battery isn’t new either, Any car of that age is prone to radical electrical issues anyway – my car is 21 and i rebuilt the entire electrical system when it turned 14, and your car has way more electronics than mine.

  • Michael Mahan

    Okay I have a question too. So a last week I left my high beams on overnight and it killed my battery. I tried to charge the battery but it wouldn’t charge so I took to Autozone so they could charge it. They told me the battery was dead so I bought a new one. So a few days ago I left the high beams on overnight again and the battery died again. I tried to jump start it but it didn’t work so I went back to Autozone and they told me that this battery was bad too. Something seems off because people get dead batteries all the time and are are able to recharge them but mines all of sudden die one time and they’re bad. I’m not buying that anymore. Anyone have any ideas on what’s going on?

    • Shaun Webb

      of course when you leave the lights on your battery will die as it is not being charged. Just because a battery is dead does not mean it needs to be replaced. Do you throw your phone or laptop out when it runs out of battery? Charge the battery or jump start the car and it will work fine.

      • Michael Mahan

        See that’s the problem. I tried to jump the battery myself and it didn’t take any charge. Next I took it to Autozone so they could jump it for me but they told me it was junk. I then bought a new battery and the exact same situation happened again. How could two batteries turn into junk from dying only one time since I had them?

    • Dash Matterson

      Car lights are not intelligent, which means the will drain your battery completely dead if left connected long enough. The circuit is closed with huge resistance. Unlike you phone or laptop which runs through an intelligent circuit that prevents complete drain. For a battery to be raised from the dead it needs a small +/- 2% of internal charge, together with some battery-charger TLC. The average autozone ain’t got the time, they’d rather have your money. Bottom line don’t leave your lights on.

  • Gary Moser

    My light come on but it will not re star why

  • Total Car Collections

    A car battery is one of the most important parts of a car. In the sense, it is as important as the car engine, because without it, it is impossible to start the vehicle without having to push it from behind. It is the heart of the car and movement begins when car batteries function the way they’re supposed to.

  • Samantha Lara

    My battery is new and so is my alternator i got my battery charged to 12v in 3 hrs it goes under 10v and dies while moving its Cadillac Eldorado before I charged it it wouldn’t hold a charge after a jump

    • Mike Williams

      My suggestion is while you have a warranty take the battery back and have it replaced. Just because a battery is new to you doesn’t mean it hasn’t been sitting on a pallet for months discharging waiting to be bought. Just to be proactive you may also check the alternator again as well again new doesn’t mean functioning properly. But the battery not being able to hold a charge is defective unless there’s a significant draw on it with the car turned off.

    • Jonathan Joy-Pagliarulo

      Make sure that the housing unit that harnesses the battery in place is tight or the battery will jiggle while you are driving and it will loosen the cables which you need to make sure are tight at all times on to the terminals. If that isn’t your problem, it could very likely be corrosion inside of the wire that goes from the batteries positive or negative cable/heavy gage wiring, it could be both. You just need to take a look at the wiring where it connects to the terminals on the positive and negative and if you see corrosion cut the wire and see how far back it goes and either clean it or replace it. AlsoAlso make sure that connect to the battery are not corroded. Or you could have a defective battery. One last option is that you may have a security system that is draining it while the car is off. Try just locking the doors and not activating the system. If it has valet mode, that can cause the problem too. Make sure that is turned off. Another thought, something that happened to me not long ago, was that my alternator belt wasn’t tight enough and it could also be missing teeth which will cause it to slip. Then your battery won’t be getting charged.

  • Myeshia Pugh

    If I got my battery charged is it necessary to give it a
    jump once I put it back in the car

  • Christopher Myers

    I just got a brand new battery, my car won’t start without a jumpstart when weather is below freezing, it starts just fine in warmer weather, when I jumpstart it it starts just fine,I have a remote and when I jumpstart it it tries,to start without the key in the ignition, what could be the problem and what should I do to insure my car starts in cold weather

  • Hannah

    Okay I read all this but I don’t think it’s exactly what’s going on with my car. I have a 2000 Toyota Camry Le, I had found out over 3 weeks ago that my main fuse in my fuse box completely fried itself into the fuse box. So we went to a wrecking yard and got the right part and switched it out in my car with a new fuse and wires. That fix only lasted about a day and a half and my car basically died. Figured it was the battery and even with a jump start it wasn’t enough. (Battery was bad) so we bought a new one. I was able to drive my car around for probably 6 hours that day ( helped a friend move) and once I got home everything was dim and my car was struggling to stay on. So we tested the alternator ourselves (it was bad) bought a brand new alternator (before buying we had them test my old one it was bad) and took the new battery back to have them check it (it drained and was too dead basically even if we jump started it it wouldn’t hold) so we put the alternator in put the new battery in and the battery light still flickers…. I’m 19 sadly I don’t make enough money right now to keep spending money on different parts guessing it will work… I don’t have a way to take my car to a mechanic either… if anyone has any idea of what’s going on please let me know… I don’t want to get another used car but I don’t know what other options I have..

  • Autumn Johnson

    I read this website and many others as well, and all the suggests I’ve found- I have already tried and my jeep (1999 Wrangler) still wont hold a charge. I bought a brand new battery (its a good battery and works) as well as new battery cables for both the positive and ground. I also bought a brand new ECU. I’ve had the alternator tested 5 times, at 3 different shops, and they all say it works perfectly fine. The belt is not loose, and I can’t imagine any other source that would be draining the charge (as there is not much in my jeep anyways and I took out both the lights inside during the summer). Basically what happens is, anytime I’ve replaced a new part it runs just fine that whole day. I put it in the garage and go to school in the morning and it runs perfect. The problem is on the way home, about 10 seconds after I start driving the needle gauge is all the way to the left and it usually dies in my garage before I turn it off. I’m not sure what else to try and would rather not have to keep buying parts hoping one will eventually work. If anyone has any suggests I would be more than happy to listen.

  • Chilly77

    My car wont start by its self but have a battery starter and car runs and drives fine with that. Took it to autozone and they said it was the alternator but if that was the case wouldnt my car be always dieing while driving it. Bought a cheap Multimeter to check the battery myself.

    • Leketta Marie Harris

      hey did u find out whats the problem..cause my 2oo4 dodge stratus is doing exactly what u describe

      someone just told me its my/the bypass pulley, if im spelling it right, something to do with AC compressor

  • Nick Barkley

    I have a doozy..for starters, I will be driving and all the sudden my car just shuts off. No power steering to power breaking nothing just shuts off. Then I can wait about 20 30 minutes and it’ll start back up and it’ll let me go about another 15-20 minutes before does it again. I was told it’s probably the fuel pump so I switched out the fuel pump Yesterday by myself which was my first attempt. And I went to start it and it didn’t start.. I figured I knew the problem once I installed the new fuel pump but I wasn’t sure if it would start or not with me needing just a have it mounted another quarter inch turn.. so I drop the tank again the right way I go to turn my car on and it has no juice whatsoever. The battery itself reads 11.86 without the terminals but the minute I hook up the negative to the negative on the battery it fluctuates between 3 and 5. I just tried to have it jumped and before I hooked up my ground wires to the battery,it was reading a 13.96 but I still fluctuated

Scroll to top