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Published 07:00 AM, Tue March 22, 2016

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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?

  • 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?

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