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How to Charge a Car Battery

Published Tue August 21, 2018



Charging a dead car battery seems simple, but it takes a little know-how to do the job safely. We’ll cover the order you should attach and detach the charger from your terminals, how long it takes to charge a car battery, and other helpful tips.


Getting Ready to Charge


If you’ve found that your battery is dead in the convenience of your garage, it’s time to break out the charger.


Be sure to familiarize yourself with the manufacturer’s instructions on how to use the battery charger and how to charge your car battery. Some batteries are easily accessible; however, some are under or in the fender, and some may even be in the trunk or under the seat, depending on the make and model of your vehicle.


Also, remember that even a “dead” battery must be treated cautiously. It is very easy to get a good shock if the battery does have some juice.


Before getting started, be sure you have all the tools for the job on hand. Ensure all electronics and lights are off and your car is securely parked.


Hooking up the Battery Charger 


Follow the instructions for your particular charger. Basic instructions for how to use a battery charger include:


  • Remove the negative (-) cable from the battery terminal.
  • Remove the positive (+) cable from the battery terminal.
  • Check the condition of the terminals and clean them if needed. (You may use commercial cleaners or baking soda and water. Remember to wear gloves and eye protection!)
  • Make sure the charger is off and unplugged.
  • Hook up the positive cable on the charger to the positive terminal on the battery.
  • Hook up the charger’s negative cable to the battery’s negative terminal.
  • Plug in the charger.
  • Follow your charger’s instructions to identify your battery type and set the proper amperage.
  • Turn on the charger.

When the timer sounds, or the readings say your charge is complete, turn off and unplug your charger. Remove the positive cable first and then the negative.


How Long Should You Charge a Car Battery?


Your car charger’s instructions will give you the best timetable for how long you should charge your car battery, but generally, the higher the amps going in, the faster your battery will charge. However, using a lower amperage is a slower, gentler approach that may prolong the life of your battery.


If the battery voltage is below 11.85 and your charger puts out a 5-amp charge rate, it will take about 12 hours to fully charge a battery with 400 to 500 cold-cranking amps. The same battery will take about 6 hours to fully charge if the charge rate is 10 amps. The lower the open-circuit voltage in the battery and the more cold-cranking amps, the longer it will take to charge the battery.


If a cell is bad, the battery won’t hold a charge. In this case, bring your battery or your vehicle with your battery to a local Meineke Car Care Center, and we will change your vehicle’s battery.


How to Jump a Car Battery


Jump-starting a car battery is a very similar process. Here are a few quick reminders on how to correctly jump a car battery. For more information, visit our step-by-step instructions with pictures on jump-starting a car battery.


If you look on the top of the battery, you can see which cable is which. The ground cable has a negative (-) sign, and the positive cable has a plus (+) sign.


  1. Attach the red cable (+) to the dead battery.
  2. Attach the other end of the red cable to the charged battery.
  3. Attach the black cable (-) to the working battery.
  4. Attach the other end of the black cable to the metal frame of the car with the dead battery.

Once the car is started, remove the cables in reverse order.


Visit Meineke for Expert Battery Services


If you need professional help, visit your nearest Meineke Car Care Center for expert battery services.


You can find more information about keeping your car’s battery in top shape on our blog.