How to use a car Battery Charger?


Using a car battery charger is simple. As long as you follow the instructions on your battery charger and take all the necessary safety precautions you will not have any problem. Make sure you use a charger with the correct amperage for the battery you need to charge. Using a smart car battery charger is always better as it will prevent overcharging and reverse polarization.

Charging a car Battery 2 amp or 10 amp

The most basic car battery chargers will offer a charge at 2 amps and because the amperage is so low it will need at least 24 hours of charge to deliver the 48 amps your battery needs to completely charge if it was totally flat. There are a wide range of battery chargers ranging from 2 to 10 amps and the higher the output of amperage from your car battery charger the faster you will be able to charge your battery.

A car battery holds about 48 amps and it will charge at about 1 amp per hour, taking this into consideration you can work out how long it will take to charge your battery using the different amperages on your car battery chargers.

If you are going to be charging your battery at 10 amp then it will charge fairly quickly and you should be sure to switch your charger off after 1 to four hours to ensure that you do not overcharge your battery and damage it. There are battery chargers that will automatically turn down the current to a lower amperage when the battery is full, these are maintainers and put out trickle charge to ensure your battery remains at a charged level.

Charging a car Battery While still Connected

You can leave your battery connected when charging if you are using a trickle charger which is designed to keep your battery at a certain level of charge for extended periods. If you are using a full charge then it is best not to keep your battery connected while still connected for safety reasons.

Obviously if you are trying to jump start your car at the side of the road then removing your battery is not practical and it is quite safe to jump your battery while it is still connected to the car. Also it is good to keep in mind that should you disconnect your battery you will likely lose your radio code as well as your security code on some cars.

Charging car Battery Overnight

With the new smart car battery chargers leaving your car battery charging overnight is no longer a problem. These smart chargers will charge your battery until about 80% full and then switch to trickle charge to completely charge the battery which takes a long time. Once the battery has reached capacity they will switch off automatically and monitor the charge in your battery, only switching themselves on again should the charge drop below a certain level.

If you are charging your battery with a high voltage charger that is not a smart charger offering different amperage and the option of maintaining your battery then it would not be advisable to charge your battery overnight as you run the risk of overcharging which will damage you battery.

Also it is important to ensure that you are charging your battery in a well-ventilated place and ensure that you do loosen the vent caps which will allow the gases that the battery will produce while charging to escape which is a necessary safety precaution.

How to use a battery charger 12v

Using a charger on a 12 volt battery is the same as using one on other amperage batteries. You must make sure that you have a battery charger that can properly charge a 12 volt battery which is the standard voltage on a motor vehicle. A 10 amp charger is the best one to use with a 12 volt battery to charge it fast and efficiently. You can of course use a higher amperage to get a really fast charge. An 80 amp charge will charge your 12 volt car battery in an hour and a 40 amp will charge it within 1 to four hours depending on how depleted your battery was to start with.

When using the higher amp chargers you need to make sure that you do not overcharge your battery and damage it. Be sure to unplug the battery charger once you have finished charging your battery unless you are using a smart charger that will automatically lessen the current flow when full charge has been reached. However you can also use lesser voltages if you are not in a hurry to charge your battery or if you just want to maintain it at a full level using a trickle charge.


Using a car battery charger is simple and easy. Follow the instructions on your charger and make sure that you are using the correct amperage that is compatible with your cars battery and you will not have any problems. These great devices make your life a little easier and prevent you from struggling as you are left stranded with a flat battery. The best car battery chargers will also maintain your cars battery so you never have to end up with a flat battery.

We hope you enjoyed our article on "How to use a car Battery Charger?", if so, please share and rate it.


    Leave a Reply