How Long Does It Take To Charge A Car Battery? Detailed Answer

How Long Does It Take To Charge A Car Battery
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A flat car battery is the last thing you want on the road. Without a functioning battery, your vehicle won’t start. Giving it a jump start or calling a roadside maintenance service are your options, yet less than ideal.

Fortunately, you can easily avoid these mishaps by recharging the battery yourself. So, how long does it take to charge a car battery?

How Long Does It Take To Charge A Car Battery While Driving?

The fastest way to charge the battery is to drive the car. When you set your vehicle in motion, the power the engine generates is channeled through the alternator to charge the battery.

Car Alternator

Car Alternator

Before this happens, you will need to crank up the engine’s RPM (revolutions per minute) beyond 1,000 RPM to generate enough extra juice for the battery.

So, how long does it take for an alternator to charge a battery? Charging your car battery while driving is faster than using an external car battery charger. Driving 30 minutes straight can give the battery enough juice to function after turning your vehicle off and restarting it again.

It’s possible to get the car battery back to its full capacity if you drive for an hour with headlights, radio, and other electrical components on. Technically, the higher the speed you reach, the more RPM is generated, and thereby the alternator will charge the battery at a faster rate.

It means that you should drive on a highway or empty, open road where you can maintain the high speed for an extended period to charge the battery fully.

Driving On A Highway To Charge Your Battery

Driving On A Highway To Charge Your Battery

Different Charger Types And Their Charging Times

With an external charger, how long does it take to charge a car battery? The answer might vary depending on the type of car battery chargers you use. To be more specific, the more amps your charger sends to the battery at a given time, the less time it takes to charge.

Linear Battery Charger

The linear charger is a simple charger type that lets your battery charge through a wall socket. It runs at low amperage, which means it takes quite a long time to charge a battery from flat to full.

So, how long does it take for a battery to charge with a linear charger? On average, it takes 12 hours to charge a 12-volt battery, which is commonly found in most cars.

This charger is the cheapest among all charger types. As the name suggests, it charges your car battery in a linear stream without any controller to stop the charge.

Hence, you want to keep a close eye on it to prevent overcharging. Or else, you risk reducing the battery’s lifespan, and even worse, an explosion in certain situations.

Multi-Stage Battery Charger

Multi-chargers outcompete their linear counterparts in several ways. They are a better choice to keep the battery cells healthy since the power comes in bursts, so there’s less damage to the battery than linear charging.

Also, these chargers automatically stop when the battery is full, meaning you don’t need to worry about overcharging issues.

Multi-Stage Car Charger

Multi-Stage Car Charger

Not to mention that multi-chargers are the fastest among charger types. They can reach up to 50 amps to quickly charge a regular car battery (no longer than an hour).

Trickle Charger

Trickle models charge car batteries at a much lower amperage, between 0.8 and 4 amps. This type of charger is meant for keeping the battery in a stable state when not in use for a prolonged period. On the flip side, it does not work for flat or deeply discharged car batteries.

Trickle Car Charger

Trickle Car Charger

A trickle charger that runs at 1-2 amps takes as long as 48 hours to get a car battery to its full capacity. The good news is that there’s no risk of overcharging, so you can leave the charger connected to your battery for days or months to keep it in prime condition all the time.


Frequently Asked Questions

How Long Does It Take For A Bad Alternator To Drain A Battery?

A faulty alternator does not drain a battery, but it acts as a bridge between the battery and the power supply. Once it stops working, your battery won’t recharge as you’re driving.

Your car will eventually come to a halt once the battery is exhausted. The battery on gasoline-power cars might last from 30 minutes to 2 hours.

How Long Does It Take To Jump A Dead Battery?

Before seeking professional help or replacing your dead car battery, you may want to jump-start your vehicle. You will need jumper cables and the battery of a “donor” car to help you out.

After connecting the leads in the correct order to car battery terminals in both batteries, you start the donor car. Wait a few minutes, turn on your car. If it doesn’t start, you should spend several more minutes waiting and start again.

When your vehicle starts, it is recommended to run it for more minutes to give extra juice to your battery. Once disconnected from the donor car, your car should run nonstop for 30 minutes to ensure that it won’t need another jump start when you stop again.

How Long Does It Take For A Car Battery To Die With The Lights On?

The battery can last from 30 to 90 minutes with headlights on. A dead car battery means you can’t start the vehicle, but the lights will still run for several hours.

How Long Does It Take To Charge A Car Battery After A Jump?

As mentioned, you need to replenish the exhausted battery by driving for at least 30 minutes. This period allows the alternator to charge the battery sufficiently so that the car will start again the next time you turn it off.

If your battery has gone flat for a while, keep the car running for a little longer to ensure it won’t easily die again.

The Bottom Line

How long does it take to charge a car battery? The answer depends on what type of charger you’re using. It can take you as little as an hour to 1-2 days for your flat battery to charge up.

Car battery does not require much maintenance; as long as you keep it fully charged, it will serve you at its best.

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