How Long Does It Take to Charge a Car Battery?

For a lot of drivers, starting up your car only to find the battery is dead is a real nightmare scenario. Your car’s battery is the electrical heart of its operation. Without it functioning properly, you can’t hope to even get started on a journey of any length. There are several possible factors that will lead to the power being drained from your car’s battery. For example:

· Leaving lights on or a/c running when you leave the car

· Not using the car for long periods of time such as two months or more

· Loose connectors or corrosion

· A faulty alternator

· And many more…

If your battery does lose power, then the task of recharging it becomes necessary. The important question for many is not necessarily how to do that, but rather how long does it take to charge a car battery? The answer to this question depends on many factors, which we will explore in today’s post.

Who Needs This Information?

For many drivers, the mysteries surrounding the question of how long does it take to charge a car battery are somewhat unimportant. When you use your car regularly, and refrain from using electronic features when the engine is not running, then you are very unlikely to find yourself in a dead- or low-battery situation. For others, the situation is rather different.

1. Owners of older cars whose car batteries are nearing the end of their lives.

2. Drivers whose car batteries have sustained damage or corrosion

3. Owners who frequently leave their car unused for lengthy periods

If you fit into one of these three categories, then the following information will be crucial to you. It’s essential that you plan battery charging properly so as to be able to get sufficient charge in the time you have.

What Chargers are Available?

Broadly speaking, there are three types of common car battery charger that drivers use. They are:

1. Multi-stage chargers

2. Trickle chargers

3. Linear chargers

Let’s look at each of these in turn, how they work, and what kind of timeframe you’re looking at when using them to charge a dead or dying car battery.

Multi-stage Chargers

Among car battery charging options, these are among the more expensive items. You can expect to pay $100 or more for one of these. The premium you pay is worth it if you are having to charge regularly, because the multi-stage charger is better for the overall health of your battery than others, especially the linear charger.

This one works by using its up to 50 amps of power to charge in a series of staggered bursts rather than in a non-stop stream of energy. The cells in the battery benefit greatly from this approach, and it’ll help extend your battery life when you are charging frequently. Better yet, the strong available power rating means you can be charged up inside of an hour.

Trickle Chargers

For the driver with more time to spare, the trickle charger is the ideal choice. The run of a much lower amperage than multi-stage chargers at only 0.8 to 4 amps. The lower output makes these ideals for those who are just “topping up” the battery rather than charging up from dead or near zero. As the name suggests, the charger releases a small amount of power continuously and can take up to 12 hours (using a 4amp charge) to fully charge the battery.

Trickle chargers are available online for as little as $30, but can also range up to $50 or a little more depending on brand and power rating.

Linear Chargers

These are certainly straight-forward and easy to use, but like trickle chargers feature a low power output of around 1-10 amps depending on the exact brand and model. The Noco Genius 10-amp charger can get you fully charged in around 2-3 hours, but of course, the exact time will also depend on other things.

Such chargers are more expensive at around $90-100. Cheaper ones will offer smaller power outputs, thus extending the overall charging time. There’s a great choice out there, so you can take the time to find a model and price that suits your needs.

So, How Long Does It Take to Charge a Car Battery?


In this section, we’ll deal with using chargers mentioned above. As we’ve already touched on, the overall power output of the charger you are using, as well as the style of charge (continuous or multi-stage) will have the most immediate effect on the predicted length of your overall charge time. To take a regular-sized 12V battery, for example, from zero (or near zero) to fully charged will take the following approximate times for each power rating to finish:

· 2 amps — As long as 1-2 days

· 4 amps — Roughly 12 hours

· 10 amps — Around 4-5 hours

· 12 amps — 4 hours

If you’ve done the math, you’ll realize there’s a pattern. A standard battery typically holds around 48 amps. The power rating indicates how many amps can be charged up per hour, so from there you can work it out. There are differences, of courses for smaller car batteries. Something like an RC 40-60 is a small battery, and so a 10-amp charger could, for instance, finish that in approximately 2-3 hours. Equally, larger batteries (RC85-190) would take the same charger as long as 7 hours to finish.

You should also note that these ratings above indicate the length of time it would take to charge a dead or near-dead battery. If your battery already has some charge, then you can deduct from the total charging time accordingly.

How Fast Does My Car Battery Charge While I’m Driving?

As we have already said, regular use of your car will help to keep the battery charged, and you won’t need to use a charger to keep power levels in the optimum position. If your battery is at low power, then driving it is a great way to charge it back up without resorting to purchasing and using chargers. You may be wondering, therefore, ‘how long does it take to charge a car battery when driving?’ It’s a fair question, let’s explore the answer.

There are two critical factors that will help us to understand the rate of charge that our car battery is experiencing during regular use. They are as follows:

1) How often and for how long we use our car

2) How much charge it has when you set off

First, the way we use our cars greatly impacts the charging time or how drained it will become. If you are the kind of person that drives the kids to school every morning, drives to the office, and/or takes the car out on regular excursions on weekends and holidays, then it’s safe to say that your battery will nearly always be well charged, and won’t require long at all to reach or stay at safe levels. If you need to charge it up, however, then you can start by just starting your engine and idling for a while. Taking the car out for a drive will also build up-charge in the battery.

In the latter case, however, you will not be able to get the battery up to high levels of charge. What you can do is get to a decent level, and then complete the rest of the charge with a multi-stage charger to get back to optimum high-power levels. This is a useful process to do — drive and then charge — when you have accidentally drained a lot of power by leaving on internal lights, a/c, or some other electrical system.

Second, how much charge the car already has when setting off is also an important factor to consider in overall charging time. Starting from a low point, your goal should be to drive in high-speed lanes without using any other electrical systems like the stereo, air conditioning, or interior lights, for around 30 minutes. That will offer your battery a good deal of charge. If your only option is driving in traffic, then the same conditions above but with drive time extended to about an hour should offer a sufficient charge.

If the Battery is Truly Dead – Call a Mechanic

car-battery-Mechanic How Long Does It Take to Charge a Car Battery?

The one other situation that you might deal with is a truly “dead” battery that won’t start at all. In that case, you won’t be able to use idling or driving as a method of charging. In these circumstances, the battery will require a jump start in order to provide that initial burst of energy the battery needs to get the engine going. After that, the running engine will do its work to begin recharging the battery. It is not advisable to try this yourself unless you have automotive repair experience. Call a mechanic or other knowledgeable professional with experience to help you set up the cables and perform the jump start wherever you are. After that, you can drive it around to get some power built up, but then you should visit an auto shop to check on the battery for potential damage, or the possible need for replacement.

So, how long does it take to charge a car battery? In reality, it should take as long as you can give. This way, you avoid unnecessary strain on the battery itself. The battery is the electrical heart of your vehicle engine. Don’t let the power level get too low, and never take any risks when trying to get it charged back up again. When in doubt, always call in the professionals.

Share Your Love

Leave a Comment: