How Long Does It Take to Charge a Car Battery?

If your car battery dies, it’s important to know how long it will take to charge it fully. How long does it take to charge a car battery?

In general, it takes about 4 to 11 hours to fully charge a dead car battery with a 10 ampere (amp) charger. If you are using a 2 amp charger, it will take about 2 to 4 days to charge.

You don’t need to fully charge your car battery to make it work. You can charge it just enough to drive to a mechanic.

Read on to learn more about how long it takes to charge a car battery including the factors that affect the charging time.

How Long Does It Take to Charge a Car Battery?

It takes about 4 to 11 hours to fully charge a car battery with a 10 amp charger. However, if you are using a 2 amp charger, a car battery will take about 2 to 4 days to charge.

Keep in mind that if different charging methods fail to work, the battery might be damaged and need to be replaced.

The time it takes to charge a standard 12-volt car battery depends on the amperage of your charger. See below for different lengths of time it takes to charge a car battery, depending on how many amps the charger is.

2 Amp Charger

How long does it take to charge a car battery at 2 amps? If you try to fully recharge your vehicle’s battery using a 2-amp charger, it might take you 1 to 2 days to do so. The reason is that such a charger provides 1 amp per hour only.

A 2 amp charger is suitable if you intend to leave your vehicle connected to the charger over time. This is also ideal if you don’t use your car daily.

4 Amp Charger

In general, a vehicle’s battery holds 48 amps. This means that a full charge using a 4 amp charger will take you roughly 12 hours. Many chargers have 4 amps. If you want a faster charge time, opt for a 10+amp charger.

10 Amp Charger

A half-discharged small battery may be recharged using a 10 amp charger for approximately 2 to 3 hours. When we say small battery, this is an RC 40-60.

For RC 60-85 or those that are medium-sized, a half-discharged battery may be recharged for a minimum of 4 hours. Though sometimes, it can last for 7 hours.

If the battery is 100 percent discharged, it will take you twice as long to recharge.

How long to charge a dead car battery at 10 amps? A 10 amp battery charger will take about 4 to 11 hours to fully charge a dead car battery.

15 Amp Charger

A 15 amp charger will take only about 3 to 5 hours to fully charge a dead car battery.

For an excellent 15 Amp battery charger for your car or truck, take a look at the NOCO Genius G15000 12V/24V 15 Amp Pro-Series Battery Charger:

It charges all types of 12V & 24V lead-acid batteries and 12V Lithium. Simply plug it in, and it quickly recharges the battery in hours.

40 Amp Charger

A 40 amp charger is guaranteed to recharge your battery quicker than expected. But make sure not to overcharge it. As mentioned earlier, overcharging might permanently damage your battery.

how long does it take to charge a car battery

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

Several factors contribute to the duration of car battery charging. Two of these are the initial charge time duration and the car usage cycle:

1. Initial Charge Time

The recharging time for a car battery highly depends on how long it was last charged. It also depends on several other factors, such as your car’s make, year, model, and even the last time it was used. However, in general, cars should maintain 1000 revolutions per minute.

If you’re driving on a freeway or a highway, charging time will more or less take you 30 minutes. But if there’s moderate to heavy traffic, your car battery will most likely charge for at least an hour or so. If you are charging while driving, it is best not to use the radio, lights, or other electronic devices.

2. Usage Cycle of Vehicle

The usage cycle of your vehicle contributes to how soon its battery gets drained. If your vehicle is left unused for quite some time, the chances are that its battery will run out, unlike when you use it often. The same thing happens if you leave the car aircon or the lights on.

Did you know that when your car is left idling, the battery is charging at its best? For as long as the alternator is not faulty, car idling helps to recharge the battery partially. If not, try driving around for a few minutes to help your battery recharge.

If you want your battery to recharge fully, it is recommended that you use a multi-stage charger.

how long will it take to charge a dead car battery

Various Types of Car Battery Chargers

You need to know the different types of car battery chargers to be familiar with the corresponding charging time. It is possible to charge your battery for only one hour, and it is also possible for you to take days to finish charging. It all boils down to several factors, such as the charging method you use, the type of battery your car has, and the type of charger you use.

Let’s talk about three different car battery chargers: the linear charger, the multi-stage charger, and the trickle charger.

1. Linear Car Battery Charger

The linear charger is the simplest form of a car battery charger. This device only needs a wall socket to charge your car battery. Since it is the simplest, it follows that it is the easiest method as well.

Unfortunately, this simplest method does not mean that it is also the quickest method. It works at a low amperage since it has a low requirement for set-up and power. Evidently, it takes a long time to charge.

The cheapest linear charger operates at 2.7 amp. If you use this, it will take you a maximum of 12 hours to charge a 12-volt lead-acid battery. This battery option operates at a continuous charge as well. It is not equipped with a controller to stop it from charging when the battery reaches its peak.

This means that you have to closely monitor while charging is ongoing. If it exceeds charging time, it will most likely damage your battery’s longevity. And the worst-case scenario is that your battery might explode.

2. Multi-stage Car Battery Charger

Compared to the linear charger, the multi-stage charger is more costly. Its price ranges between US$90 and US$110.

The linear one recharges in a continuous stream, while the multi-stage version recharges in bursts. This is a more recommended method as it prevents the battery cells from getting long-term damage. Car batteries are prone to this kind of damage when using the linear charging method.

This multi-stage charging method is also referred to as the intelligent charging method. It is mainly because of its capability to do burst charging and due to the higher amperes. Multi-stage car battery chargers with a maximum of 50 amperes are available in the U.S. market. With such a maximum capacity, it will allow your battery to charge within an hour.

3. Trickle Car Battery Charger

The trickle car battery charger runs between the range of 0.8 and 4 amperage and operates at a low power output level. This can’t be used if your car battery is totally dead or drained. Instead, it is best used before such a problem occurs.

This charging method is ideal for preventing your car from breaking down, especially when you are somewhere far from home. If you feel that your car battery is running low, you should recharge it using this method while the vehicle is not in use.

The trickle charger is ideal for the Enhanced Flooded Battery, or what is commonly known as the EFB. This battery can be charged fast at low voltages. Charging must be done while the vehicle is not in use or when the battery is half-drained. Similar to other methods, overcharging must be avoided.

How Long Does It Take for a Car Battery to Charge with a Trickle Charger?

A trickle charger operates at about 2 amps, so it will take about 24-48 hours to charge a 12-volt car battery. It can take as long as 4 days to get the battery up to an acceptable charge with a trickle charger.

The trickle charger is ideal for long-term use. With this charger, you can maintain battery levels regularly using low power. Trickle charging is a method generally preferred by owners and drivers of motorcycles, all-terrain vehicles (ATV), and recreational vehicles (RVs).

In general, this type of charger makes use of 1 to 2 amps only. Apparently, the process is slower than when you use a higher amperage charger. So charging time can take you roughly 48 hours.

how long does it take to charge a dead car battery

What vehicle owners and drivers like about the trickle charger is that it doesn’t overcharge. The battery won’t overheat too.

To specifically determine the duration of trickle charging your vehicle, it is indicated in the spec sheet. If you want to confirm it, you can make use of an automotive battery tester.

Generally, drivers estimate the time by checking the minutes left in their battery, the reserve capacity, the voltage applied, and the latest battery percentage.

How Long It Takes to Fully Charge a Dead Battery

It is possible to charge a dead battery. In fact, you can even fully charge them. The quickest duration is approximately 4 hours, but it is also possible to take you 24 hours — or even more — to finish charging. It all depends on the car battery’s size and the power of the charger you will use.

But then, you don’t have to fully recharge your battery to start your vehicle. In case you are in an emergency, charging it for an hour using a standard charger is already expected to be enough.

Why Do Car Batteries Fail?

There are different reasons behind a drained or failed car battery. Here are some of them:

  • Your battery may be experiencing charging failure. Expectedly, your battery should be charging while you are driving. But if you don’t drive long distances that often, there is a likelihood that it won’t get charged by the alternator.
  • If you use the in-car features over time while the car is not in motion, your battery can get discharged. Using the air conditioning or listening to the radio — or doing both — drains the battery fast.
  • When you’re in a hurry, you tend to forget to turn the headlights off. In this case, there’s a huge possibility that your car battery will get drained. This is especially true if you leave it on for hours. This is why most car manufacturers, if not all, have an automatic shut-off feature for the headlight.

Conclusion – How Long Does It Take to Charge a Dead Car Battery?

In general, charging a dead car battery takes 4 to 11 hours. If you are using a 10 ampere (amp) charger, it may take you 4 to 11 hours to fully charge it. However, if you are using a 2 amp charger, it will take you 2 to 4 days to charge. But then, you don’t need to fully charge your car battery to make it work.

The trickle charger is the most recommended among the three types of chargers, as it prevents you from overcharging your car battery. Suffice it to say, it also prevents the battery from getting damaged easily.

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