Car Battery Charger: How to Charge your Car Battery With a Car Battery Charger

Have you ever been on the road and had to seek professional assistance because your car battery is having problems? If you’ve experienced this before, you’ll be glad to know that all you need to resolve such car battery issues is a car battery charger.

With that in mind, you’re probably unsure what battery charger to get or how to operate one. Read on to learn how to charge your car battery via a car battery charger.

Types of Car Battery Chargers

Below are the three types of chargers and their respective functions.

  • Charger: The charger uses low amp charges to back up the battery in about 24 hours. However, it all depends on the output. If you often go off-road or take long drives, it’s probably best to keep a charger with you as you never know when your battery could face some complications. However, when charging your battery via a charger, be careful not to overcharge it.
  • Maintainer: maintainers continuously provide power to the battery without the risk of the battery overcharging. Therefore, you can keep it running if you want to listen to music or keep your car lights on. You could even get a solar-powered maintainer if you want to keep your battery full while driving off and on the road.

Trickle Chargers vs Battery Maintainers

In case of emergencies, it’s best to ensure you have one of the two.

Battery MaintainerTrickle Chargers
SizeNormally, they have a setting at 10 amps and another at 5 amps. Some have a setting of 75 amps, which is enough to jump-start a dead battery or fully charge your battery in 2 – 3 hours. The majority of trickle chargers provide 5 – 10 amps, which is enough to recharge a dead battery in under 12 hours. 
ProsThey function just the same as trickle chargers but offer a bit more. 

You can charge your battery without having to monitor the progress. Once your battery is fully charged, the system shuts itself off. Thus improving the lifespan of your battery.
You can select the amperage setting you want to use.
They deliver a constant current that doesn’t change over time. 
You have to manually connect it to your battery, and after some time, you have to disconnect it from your battery. Failure to do so will overcharge the battery, hence damaging it.
They’re cheap.
ConsOverloading by using excess amps could shorten the battery’s lifespan. Therefore, only use high amps when trying to jumpstart a battery.They are useless during emergencies because they can’t jump-start a dead battery quickly enough.
Trickle Charger

Caption: Trickle Charger

How to Charge your Car Battery With a Car Battery Charger

  • The first step is to remove the battery if necessary. Check the user’s manual to determine if you are required to remove the battery when attempting to charge it. If your vehicle doesn’t require removing the battery, you will likely find it in an easy-to-spot position. However, if your battery is found in your trunk, under the seats, or under the fender, you’ll likely need extra tools or professional help to remove your battery.
  • The next step is getting the appropriate charger.
  • Connect the charger’s positive cable to your battery’s positive terminal.
  • Connect the negative cable of the charger to the negative terminal of your battery.
  • Set your charger at the slowest charging rate.
  • Turn on your charger and set the timer.
  • Once the timer runs out, disconnect your charger after ensuring it’s off.
  • Finish by disconnecting the cables.
Jumper Cables

Caption: Jumper Cables

How Long Does It Take to Charge a Car Battery?

Divide 48 by the number of amps your charger offers in order to obtain how long it will take to fully charge your battery. For instance, if your charger is capable of supplying 6 amps an hour, then your battery will need 8 hours to fully charge.

However, before you jump into charging a battery, it’s important to determine if your battery is worth saving.

To begin with, if a battery is over three years old, it’s probably better to replace it since the majority of batteries last up to four years. Also, climate affects battery life, especially in extreme weather conditions.

Therefore, if you live in an area that often experiences extremely high or low temperatures, your car battery has a shorter lifespan than normal.

The extreme heat during the summer causes battery fluids to evaporate, thus reducing your battery’s effectiveness.

However, this isn’t as severe as during the winter when temperatures drop drastically, causing fluids to thicken; therefore, your battery needs more energy just to start.

Also, if the battery is already completely dead, it’s permanently damaged and could leave you stranded anytime. In such a condition, a slow charge is the better way to restore it. If you use a charge that’s too fast, it could damage the battery.

Are Car Battery Chargers Universal?

The term universal in terms of battery chargers is rather misleading. Although there are a number of universal battery chargers, none of them is capable of charging every type of battery.

One type could be capable of charging almost any standard household battery, another could charge almost every type of cell phone, and another could charge almost every industrial battery.

Therefore, each charger is universal in a certain sense since a universal household battery charger probably can’t charge cell phones or other similar gadgets.

Often, your car will have a lead acid battery unless it has numerous electronics. If that’s the case, your car probably has an AGM battery.

Vehicle battery chargers are available in various designs that offer various features. However, any functional battery charger should charge any type of car battery.

The core principle behind any type of charger doesn’t change. Every battery charger has two cables with a clamp at the end that you use to connect to your battery.

The black represents the negative charge, while the red cable represents the positive charge. 

All you need to do is connect the cables to their respective terminals on your battery. If you’re unsure, the positive terminal usually has a + label.

Once you connect the negative terminal to the negative terminal on your battery, you complete the circuit. Then, all you have to do is turn on your battery charger to begin charging your battery.

How to Choose a Car Battery Charger?

As previously mentioned, you can use almost every battery charger to charge your car battery. However, with the proper design and features, you can enjoy optimal charging and prolong your battery’s life.

What Size Battery Charger Do You Need?

The more power your charger can generate, the faster your battery will charge. However, using excessive amps could damage your battery. Therefore, only use the necessary amps to charge your battery.

Battery ChemistryRecommended Charging C-rateAverage Charging Time
Lead-acid batteries (GEL and AGM)Between 0.1-0.25C (should not exceed 0.3C)Approximately 10 hours
Battery Capacity0.3C Charging Rate (approximately 6-8 hours to charge)0.25C Charging Rate (approximately 8-10 hours to charge)0.1C Charging Rate ( approximately 10-12 hours to charge)
20 Ah6 Amps5 Amps2 Amps
50 Ah15 Amps12.5 Amps5 Amps
80 Ah24 Amps20 Amps8 Amps
100 Ah30 Amps25 Amps10 Amps
120 Ah36 Amps30 Amps12 Amps
150 Ah45 Amps37.5 Amps15 Amps
200 Ah60 Amps50 Amps20 Amps
250 Ah75 Amps62.5 Amps25 Amps
300 Ah90 Amps75 Amps30 Amps

Chargers With a Built-in Battery vs. Ones Without a Battery

It’s advisable to get a charger with an inbuilt battery; therefore, you can use it to jump-start a dead battery, eliminating the need to ask fellow drivers on the road for assistance. 


You have all you need to know about the car battery charger. Also, for all your car battery charger cable needs, feel free to contact Cloom Tech.