How to Recharge a Car Battery: Tips for Optimal Charging

January 27, 2016

A jump start isn't the only way to recharge a car battery, and it's not necessarily the best way. Find out how to charge a car battery the right way.

Car Battery Recharging

You can recharge a car battery when your car refuses to start. On average, most batteries do not require a recharge for at least five years. That's if you're taking good care of your car. Frequent recharges indicate that your car battery is of poor quality or that you are not taking care of your car as well as you should. Some batteries have a charge indicator where you can find out the state of the battery. If the indicator is clear or yellow, you have to recharge it.

Here are a few simple guidelines on how to recharge your battery yourself.

Note: Since battery acid is hazardous, be sure to take adequate precautions when handling old battery terminals to protect skin and clothing.

Use a Trickle Charger
This device delivers electricity to your battery from a power outlet in a slow, steady stream. You don't need to charge your car fast. A slow charge is much better, as batteries tend hold the charge for a longer period of time with this method. The trickle charger has an electric cord with a plug and two jumper cables with alligator clips.

Clean the Battery Terminals
Check the terminals of the battery and clean them. Remember that you should not touch the terminals if they are covered with a whitish powder. This is dried sulfuric acid and it can burn your skin if you touch it with your bare hands. Use a manual sandpaper pad to wipe around the terminals, or get a wet cloth and apply a layer of baking soda (sodium bicarbonate) to the cloth. Take care not to allow the solution to make contact with skin and clothing. Rub the terminals down with your removal system, and ensure that they are ready to receive the wires.

Remove the Cell Caps
On many batteries, you will see a series of small caps. These are known as cell caps, and they have to be removed before you can use a battery charger. These caps are either on the very top of the battery, or under a yellow strip which can be peeled on and off, some may have no caps at all. If your battery does have cell caps, they must be removed before you begin charging, otherwise gases created by charging will not be able to escape into the atmosphere.

Attach the Charger Cables
Make sure that the car is turned off and then attach the cables or the wires to the battery terminals. The charger will have two wires. The red wire has to be connected to the red or positive terminal (it might be labeled the POS terminal on the battery). The other is connected to the negative terminal or the terminal marked as NEG. Make sure that the two wires don't touch each other. This is because the wires will spark when they touch, causing ignition of the hydrogen gas that surrounds the battery. You could suffer nasty burns or even cause an explosion.

Turn on the Charger
Once both the terminals are connected, connect the charger to the electric outlet. Turn on the current and the battery will charge itself. Leave the charger on overnight. In the morning, turn off the charger and then check the reading on it. If the reading is less than an ampere then you can unplug the charger.

Check the Battery
After recharging, check the battery to find out whether it works. Use a hydrometer to find out the amount of electric energy in the fluid or turn on the engine. If the battery still does not turn on, then you might have to get it replaced.

Related Questions and Answers

Can you Use a NICd Battery for Charging an Auto Battery?

Yes, there is no issue using a nickel iron, or NICd, for battery charging. Deep cycle, nickel iron, or marine batteries can all be used to charge an auto battery, should the need arise. The main factor is the cranking amps generated, and it may take these batteries longer to charge than using another car battery or a battery charger. However, there should be no problem using a NICd battery to start or charge a car as long as you can generate the cranking amperage to do so.

Can You Recharge a Car Battery that Ran Out of Water?

Recharging a car battery once it has run out of water is possible, but it may not continue to hold a charge. This is solely dependent on the amount of time your battery has been running dry. Some batteries, when refilled with distilled water, will continue to hold a charge, whereas others will not. The determining factors for this are the amount of time your battery has been dry, the quality of your battery and how old it is. Unfortunately, you can only determine the answer by charging it and watching to make sure it is holding a charge. You should definitely re-fill the battery with distilled water prior to charging it.

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