How Long Does It Take To Charge A Car Battery At 40 Amps

We are answering how long your car battery get charged at 40 amps.

Have you tried charging the same car battery using two different battery charger? If yes, you will definitely know the difference between charging a car battery using a charger in two different levels of amperage.

A friend of mine asked me yesterday, “How long to charge a car battery at 40 amps?” He’s using the same battery charger that I have, a battery charger that can go up at 40 amps. But the thing is, we do have different batteries, and I believe that can change some factors.

So I immediately asked an expert mechanic in our city. “How long do you think a car battery charge at 40 amps?”

He answered, “It depends. Forty amps are high enough to charge a car immediately. If you wish to get up right away after a dead car battery, you really need to maximize the 40 amps. Even a flat dead car battery will get up running in an hour or less at that high amperage.”

Then he added, “However, it only works for certain battery charger, and there’s still a compatible battery charger to each car batteries. Also, if you will use a trickle charger, it is also a different scenario and would take longer than the normal charging time.”

Car Battery Charged At 40 Amps

Have you tried charging a car battery and it took you so long to get back on the road again? Or have you experienced being on a long road trip and suddenly your car battery went off, and you have no clue what to do because you only have a trickle charger with you?

The thing is, if you use a charger that is fit with the car battery, it will only take an hour or less if the battery is being charged at 40 amps. A battery charger and the car battery itself needs to be compatible with each other. These kind of battery chargers are those that are best for traveling longer distances.

If you are moving from East to West coast, these types of chargers are the best to go with, even if your car battery is flat dead, it will immediately boost it up, and you no longer need to wait for another day to go back on the road.

However, since this battery chargers are fast charging, you need to look out for it not to overcharge. We advise everyone to be mindful of it not to connect for an extended period to avoid a more severe problem. You don’t want a car battery exploding in the middle of your trip or while you are sleeping on your campsite.

Can We Use A Trickle Charger To Charge A Car Battery?

Can we use a trickle charger? Of course, yes. However, it usually charges at around two amps only and a 12 V car battery would be able to get fully loaded for a long time. It can take one whole day or 24 hours to fill it up or at least get charged an acceptable percentage of energy needed to keep the car running.

A trickle charger is often used just to keep a battery fully charged for a specific period. It is commonly used during winter months when you need to regularly check your battery on its storage and keep it fully charged.

It really takes a long time to charge a battery fully; however, the best thing with this trickle charger is that it automatically switches off once fully charged – thus, preventing the battery to overcharge.

These type of chargers are often used in shops to support batteries while someone works on the car and yes, during winter months when it is being stored in a warmer place.

Top 3 Battery Chargers That You Can Use

• Battery Tender 021-0123
• Schumacher SE-SE-4022 2


The answer to the question, “How long to charge a car battery at 40 amps?” has been answered now. The measure of time that it needs for a car battery to get full depends on the size or the amperage of the battery and the amperage of the car battery charger that you have available on hand.

If you are going to use a trickle charger just like the ones that most of us use during the winter or in the auto shops, then, it would take you a long time to completely charged the battery and you cannot use the car immediately even if you want to – as it usually takes 24 hours yet to reach the peak of the battery life.

We also need to pay attention to how these chargers are connected to the batteries especially those chargers that can fully charge a car battery in less than an hour or so. This means that they are also prone to overcharging and we also need to observe that.