Custom Lithium ion Battery Pack

Battery Ampere-Hour Calculation-Introduction and Method

Mar 05, 2021   Pageview:80

Battery ampere-hour is a type of rating that shows us the capacity of a battery. In other words, battery ampere-hour is the rate at which a battery can provide amperage for one hour. Basically, the amount of current that can be provided to a battery for a certain time is referred to as the ampere-hour rating. The ampere-hour calculation can be calculated by multiplying the current and the discharge time in hours.

Another method of calculation is the use of a battery calculator. The other method is explained in the article below. The process is very easy, but one that needs a lot of consideration from various factors, and missing any of the factors may lead to bad results.

What is ampere-hour of battery?

As mentioned earlier, an ampere-hour of battery is the amount of energy charge in a battery that will allow one ampere of current to flow for one hour. On many occasions, Amp-hour is abbreviated as (Ah), and it’s used as a unit of measurement. When the current flow for one hour, it is measured in amperes.

Ampere hour always shows the rate at which a battery takes to discharge. AH is used for big batteries, while for smaller batteries, a milliampere-hour is used as a rate of measurement. With the milliampere, for example, a 600 mAh battery will use or release 600 milliamps of current for a specific voltage for an hour before it is discharged.

In other words, amp-hour refers to the capacity of a battery. Amp-hour also refers to how long a battery will last when it is connected to the equipment it is powering. Most of the batteries will have the unit indicated on the battery. It is important to know that unless you know the features affecting your battery, then you may have your amp-hour all wrong.

All these features you need to be aware of include; the temperature at which your battery is being tested, the hourly rate is used, the battery power, and lastly, you need to be aware of the end voltage of your battery.

Note that it is essential to know the temperature in which your battery was tested, as different batteries vary in performance depending on the room temperatures they are exposed to.

24V Emergency Starting Power Supply,Low Temperature Large Current
Low Temperature Large Current 24V Emergency Starting Power Supply Battery specification: 25.2V28Ah (lithium battery) , 27V300F (supercapacitor pack) Charging temperature:-40℃~+50℃ Discharging temperature: -40℃~+50℃ Starting current: 3000A

How do you calculate battery time?

One way of calculating battery time is through the use of a battery calculator. This calculator will basically calculate the life or the length at which a battery can last.  Battery time, or in other words run time of a battery, is dependent on a lot of factors. Supposedly all the factors considered are efficient; the formula to calculate battery time would be; (10 times battery capacity in amp hours) divided by the appliance load in watts.

A good example is finding the battery time of a 100-watt television where the battery is rated 60 amps hours. The formula mentioned above is used, and thus (10 multiplied by 60) divided by 100, which results in 6 hours maximum run time.

Battery time may also be battery discharge time which is calculated by dividing the Ah or mAh rating by current. If you have the capacity of your battery and current, then the calculation of your battery discharge time is very easy. Time is taken to charge the battery however differs with the battery chemistries. A good example of calculating the time of charging your battery is using a 100 AH battery which has 10 Amperes current.  The calculation is done simply by dividing the capacity and current, which in this case will result in 100Ah/10 A, and the time will be 10 hours.

Low Temperature High Energy Density Rugged Laptop Polymer Battery 11.1V 7800mAh
Low Temperature High Energy Density Rugged Laptop Polymer Battery Battery specification: 11.1V 7800mAh -40℃ 0.2C discharge capacity ≥80% Dustproof, resistance to dropping, anti - corrosion, anti - electromagnetic interference

How many amps is a 100amps battery?

Most manufacturers use amp hours as a way to compare batteries and voltmeters to measure the volts of a battery. It is said that a 100ah battery should give out 1amp for 100 hours while two amps for 50 hours and lastly three amps for 33 hours. Technically it is not possible to measure the number of amps left in any battery. To get to answer the big question then, the voltmeter is what is used to give an estimate of how many volts the amps battery uses.

Since in the beginning, we refer to ampere-hour as the capacity of a battery, then we should know that the battery capacity decreases as the discharge rate increases. The discharge rate is always indicated in the batteries, and if that is exceeded, the capacity of the battery also drops. For example, if a given battery has been offered 20 ours discharge rate, it shows if five amps an hour were to be released for 20 hours, that would be 5multiplied by 20 to give you your 100 amps.

In case you manage to use less than five amps per hour, you can always get more amps than the 100 amps indicated. Always remember to get a full charge for your batteries because if you don’t fully charge them, they will interfere with the efficiency of the batteries. Always beware of the rate at which your battery draws its power because the more it draws, the lesser its capacity.

Lastly, the battery type will always determine how many amps a certain battery has. For example, if you compare Wet Cell, Gel, and AGM, you find out that each has different voltages and for the capacity of battery left.


The amp-hour calculation, as discussed above, is very easy and essential. It is good to always know the factors that may affect good results, and many have been discussed, for example, the rate at which a battery discharges its power, how many volts are used by the battery, and lastly, the battery type. Battery calculation time varies from battery discharge time to battery charge time and to how long the battery lasts.

For battery time calculation, you either need a calculator or need to get your volts and amps rate right to get the time and multiply all that by ten which is a constant value. Always keep in mind different batteries have different ratings and, therefore, different battery times.


Leave a message

Contact Us
Your name(optional)

* Please enter your name
* Email address

Email is required. This email is not valid
* How can we help you?

Massage is required.
Contact Us

We’ll get back to you soon