How To Calculate Battery Runtime?


In this article, we will try to provide you all the information about the battery runtime calculation, also above we give you a battery runtime calculator that will help you to calculate battery runtime. The Battery runtime of a car or any vehicle refers to when a lead-acid battery will last after a full charge. Different factors affect the runtime of the battery. For example, the charging system, temperature in the surrounding, and maintenance of the battery, and dirt particles can also cause a vehicle’s battery problem. A low charging system can even cause an excellent quality battery to damage.

The temperature also has a profound and deep effect on the vehicles’ battery runtime. The cold temperature increases the resistance with the increase in temperature and decreases the capacity of the battery. Maintenance of your vehicle’s battery is the key to a good runtime of the battery. There are several ways to find the battery runtime. This article will explain unique and simple ways to calculate the battery runtime at your convenience.


Ways to Calculate Battery Runtime

This article will enable you to learn about new and unique ways to calculate any vehicle’s battery runtime. Some simple and easy ways are given below that you can use for this purpose. The methods that we used are the formula for calculating run time, through calculators, and Peukert law.

1. The formula for calculating runtime

We know that the battery contains lead-acid. The most known and most used method to find battery runtime is to use a formula. According to this formula, we have to divide the 10 X capacity of the battery in amp hours by appliance load in watt. Mathematically, it is written as (10 X 60÷ 100). Some terms are challenging to understand, and their short and understandable concept is given below.

Amp-hours: It is the measure of the amperage of a battery for one hour. Amperage is the strength of an electric current. Amperage is calculated in ampere.

Appliance load: It is a load of electric current on every appliance. Its unit is the watt.

Consider you are going to a picnic, and you want to find out the time for which a radio of 90 watt that has 60 amp hours will work. You can do it by using the formula listed above. Just put the values. [(10 X 60)÷ 90]= 6.7 hours. It is approximately equal to 7 hours. We would recommend charging it after 5 hours. If you reach the time calculated, it may cause some problems in the device.

2. Peukert law

Peukert proposed this law. This law is applied to lead batteries, and it helps to calculate the runtime of the vehicle’s battery as it contains lead. He knew that the capacity of the body decreases with the increase in increasing discharge rate. Peukert law consists of the internal resistance and recovery rate of the battery.

When the runtime is calculated, if the value is equal to one (1), it represents the efficient and best battery condition. If the number is greater than one, then the battery will face some technical issues. The situation with lead batteries is not the same; efficient batteries may show numbers between 1.3 and 1.5.

Let us consider an example, a 150 Ah lead-acid battery being discharged at 15A should last 15 hours; that is the runtime. We just divided 150 by 10. An error that Peukert law produces is overcome by dividing the exponent by the discharge time.

The Importance of a Battery Check

The battery is the most crucial part of your vehicle. It may be referred to as the heart of your vehicle. All the activities in your car will stop if your battery is not good. Visiting any car store can provide your car with a good condition of the battery. A battery’s lifetime is 3-5 years. A man who travels much should make a check of the battery at least once a year. A battery function is to provide enough electricity to ignite the starter, and on each push on the button, it starts the car.

A damaged battery cannot start the car properly and can cause many problems to your vehicle. A well-maintained battery can provide a good battery runtime. If the car battery is not maintained correctly at the proper time, it can cause many complications even with your car’s charging. You can even be stranded at the roadside with your car; you can also check your car’s battery for yourself. You can test the battery with the help of a voltmeter. The volt below 12.29 is not enough for your car’s good condition.


In this article, we have described how you can find your car’s battery runtime. Among them is the formula to calculate the runtime (10 X 60 ÷ 100). If you don’t understand it, we have given an example above. You can use different calculators from browsers and Peukert law because this law is used to calculate vehicles’ battery runtime.

It is a complicated law and is explained above. A summary of it is that Peukert proposed it. It explains that if a battery has a runtime that is equal to 1, then the battery will work efficiently. However, in lead battery cases, its value should be equal to any number between 1.3 and 1.5. A battery has a life runtime of 3-5 years.

But, as we know that the more we use anything, the life goes on decreasing. A person who is adventurous and often travels should visit a mechanic of should personally check his car’s battery. It will help a lot, and there are few chances for your car to stop in case of an emergency or in an area where you fear to stop. Maintaining your car battery can protect you from huge damage.