How Long Does it Take to Charge a Car Battery While Driving?

Last updated on January 13th, 2023 at 07:25 pm

Charging a car battery while driving shouldn’t be ignored or taken as a mere task. If it becomes vital, then you can charge your car battery while driving.

Charging your car battery while driving depends on the charge prior to when you begin driving and on your driving technique.

Since your car battery is charged by the alternator, a defect in your battery is traceable to your alternator.

However, if your engine RPM (Revolutions per minute) is up, it would help in charging your battery faster.

To know how long it takes to charge a battery while driving, it may take about 30 minutes if you are on a motorway, and about one hour if you are driving in the city.

In this article, we will examine:

How long does it take to charge a car battery while driving?
How long does it take to charge a car battery with a trickle charger?
How long does it take to charge a car battery with a 6 amp charger?
How long does it take to charge a car battery with jumper cables?
How long does it take to charge a car battery while idling?

How long does it take to charge a car battery while driving?

Now let’s look at how long does it take to charge a car battery while driving by taking some factors into consideration.

· Car Usage

The call to charge your car battery while driving may depend on how you use the car.

The rate at which you use your car can lead to draining of the car battery. Your car battery may die if left for long without using it.

In the same vein, if you forget to put off your AC or car lights at night, the battery runs down by morning.

However, you can properly charge your car battery when it’s in idle mode.

If the alternator is in sound shape, then your vehicle’s power unit will be partly recharged when on idle.

To charge your car battery fully, it would require the use of a multi-stage battery charger.

Read on to find out how long does it take to charge a car battery while driving.

· Charge Duration

The time that a car battery takes to recharge depends on when it was last recharged.

The duration to charge a car cell when driving differs for different automobiles.

An RPM of over 1000 for duration would have to be sustained to achieve that.

The lower the charge in the power unit, the more duration it would require to recharge it.

Normally, when driving on the highway, it would take 60 minutes an hour for the power unit to be charged.

Conversely, when driving on a busy road, it would take up to 60 minutes or even more to achieve complete charge.

Avoid using a heater, a stereo system, lights, or an electrical device when driving and charging your car battery.

If your car battery is utterly down and fails to revive while you are driving or in idle mode, then it would require jump-starting it.

If you are unable to perform this task yourself, it is best you consult a professional technician.

This may require creating a momentary link to an exterior cell source with the intention of conveying its power to the dead battery before it resumes its normal way of charging.

How long does it take to charge a car battery with a trickle charger?

If you are planning on parking your car in the garage for an extended period of time, then you would need a trickle charger.

Normally, it takes about one whole day (24 hours) to charge your 48 amp battery to the full level.

Trick chargers typically function at around 2 amperages. Trickle chargers are essential for retaining car battery charge and ensuring the charge never drains out.

A trick charger necessitates prolonged duration to become fully charged automatically switches off when your battery is fully charged.

Auto-mechanics regularly utilize trickle chargers to retain the batteries while they fix the automobile.

This becomes imperative when power unit separation is for an extended duration, for this reason, the battery will have enough charge when mounting it back into the vehicle.

How long does it take to charge a car battery with a 6 amp charger?

In terms of amperage, the rating of a car battery charger range from 2 amp to 36 amp.

This signifies the amount of current a charger requires to supply a battery. In terms of the rapid charging rate, a2 amp is slow, while 36 amp is fast.

There’s a formula we can follow to calculate the time or how long it takes to charge a car battery with a 6 amp charger.

The formula is:
Time to charge a battery = (battery capacity x depth of discharge) amperage of the charger

For example, if the battery capacity is 54 amp and the depth of discharge is 100% or equal to battery capacity, while the amperage rating of the charger is 6 amp.

Using the formula:

The time it takes to charge a battery = (Battery Capacity x Depth of discharge) / amp of the charger

Time it takes to charge a battery is = (54 amp x 100%) / 6 amp

The time it takes to charge a battery at 6 amps = 9 hrs.

Now let’s look at this example: Change the amperage rating of the charger to 2 amp (slow charge)

Time to charge a battery at 2 amp = (54 x 100%)/2
Time to charge a battery at 2 amp = 27 hrs.

From the illustrations above, to answer the question “how long does it take to charge a car battery with a 6 amp charger”?

Based on 100% discharge rate and the 54 amp battery, the answer is 9 hours.

This means that the time to charge a battery is strongly dependent on the battery capacity, depth of discharge and amperage of the charger.

It has also been established that the lower the amperage of a charger the longer the charge.

Normally, a car battery has a capacity of about 48 amp hours. This implies that when the battery is fully charged it automatically supplies 1 amp for 48 hours, or 2 amps for 24 hours, or 8 amps for 6 hours.

The diverse mechanisms you utilize when your car is working will augment the number of amps required for the car to run.

A total of 48 amps are required to run vehicle headlights for about 8 hours. It also takes about 48 amps to run the starter of the engine for an incessant 10 minutes.

The charger charges your battery at about 2 amps. That points to the fact that the charger will boost your battery power by 2 amps per hour that it is connected.

Batteries come in diverse sizes, meaning they provide diverse numbers of amp hours.

All it requires you to do is to take the number of amp hours that your battery provides and divide 6 in that number.

The number obtained is the number of hours required to take for the battery charger to reinstate full life to the battery it is linked to.

How long does it take to charge a car battery with jumper cables?

It is impossible to charge a battery that is already dead unless you jump-start it.

Your car battery may die if you store it in freezing condition, leave it uncharged for long, leave headlights on, and other factors.

You will need a set of jumper cables to charge a dead car battery using a sound battery in another car.

Then go ahead and connect the dead battery to the functional battery using the jumper cables, and recharge the dead battery by transmitting energy from the functional battery.

After starting your car’s engine, the charging mechanism will begin to charge the dead car battery throughout the jumper cables.

Allow five minutes to pass after starting the engine of the car with the charged battery.

So, it would take a maximum of 5 minutes to charge a car battery with the use of jumper cables.

Subsequent to jump-starting your car, then drive the fixed car for about 20 minutes.

Apart from driving you can equally idle it for 20 minutes to enable the full charge the battery to get charged.

If your car battery isn’t charged enough to crank your automobile, in that case, it may require you to buy a new battery.

How long does it take to charge a car battery while idling?

It mostly takes about 2 hours to charge a car battery while idling. This is because at idle mode, the alternator can supply about 80 amps to a car battery.

This implies that you can charge a dysfunctional car battery up to 80% full in about 2 hours, as long as the alternator can produce around 14 volts at the battery terminals for the duration.

However, there are some factors that may affect this charge. They include:

the size of the battery
general health of the battery
The capacity to charge 100% or enough to start it
Charging capacity of the alternator
Quality of the connections

The engine RPM doesn’t matter since anything above idle will have the alternator at full output.

However, the power the engine is using to keep itself running, fuel pumps, computer, electric cooling fans should all be considered since they are all-consuming power while operating the engine.

Conclusion On How Long Does it Take to Charge a Car Battery While Driving

Now that you know how long it takes to charge a car battery, you should be well informed when next you face a similar issue.

Avoid leaving the electrical devices of your car ON when you don’t need it and keep your car on the run frequently to prevent the battery running dead.

The charging speed is based on your requirement. For fast charging, you can utilize high amp chargers while noting that some of these chargers might ruin your battery.

Conversely, low amp chargers necessitate a longer time to fully charge your battery, however, they are ideal for maintaining your battery over the whole duration.

Gift Dennis

Hi dear, I am Dennis Gift, an autobody repair technician with over 4 years of experience; and I love everything about fitness and cars and researching and sharing my experience. And this is where I get to do that freely without reservations. So come along with me.