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100wh to mAh Calculator-Introduction, Converting and Usage

# 100wh to mAh Calculator-Introduction, Converting and Usage

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One of the ways to know a battery’s capacity is through looking at either its milliamp-hour (mAh) rating or its Watts-hour (wh) rating. Larger batteries are normally rated using watt-hours where as those with smaller capacities are rated in milliamp-hours. For instance, you will notice that most of the electric car and laptop batteries are rated using watt-hours whereas smartphone batteries are normally rated using milliamp-hours.

And like you would guess, the higher the number of the Watt-hours or the milliamp-hours, the better the battery. The largest batteries in most electronics devices are mainly limited by airline restrictions and normally don’t go beyond 100wh. If you want to know how much this is in mAh, that is what this article is actually about. I will briefly take you through these two units and how you can covert the battery capacity rating from watt-hours to milliamp-hours and vice versa

Let’s first look at the origin of these two units of battery capacity.

Milliamp-hours

Milliamp-hours are a unit of charge that is derived from current and time. Current is basically the rate of flow of charged electrons in an electricity conductor. A higher current value means a higher flow of charged electrons in an electricity conductor per unit time.

Current = Charge/Time.

Charge = Current(A) x Time(h) = Current x Time (Ah).

From the above formula, you can see why the units of charge are Ah. But to make it easier and to avoid using lots of decimals, the Amperes are normally converted to Milliamps. For instance, it is easier to write and recall 2400mah that it would be if it was written as 2.4Ah

The Milliamp-hours rating of battery simply shows how much current the battery can produce in one hours before it gets totally drained. For instance, a 2400mah battery is able to provide up to 2400mA or 2.4A for one hour before being discharged totally

Watt-hours

Just like Milliamp-hours, Watt-hours are also used to rate a battery’s capacity. However, watt hours are not a unit of charge, they are a unit of electrical energy in the battery. The values of the watt-hour basically represent how much energy the battery is storing derived from power. Let’s first look at the formula of power

Power (W) = Energy(J)/Time(s)

This means; Energy = Power(W) x Time(s) = Power*Time(Ws)

To get Watt-hours, you have convert the time from seconds to hours by dividing with 3600. So basically Energy = Power/3600(Wh).

What is watt-hours(Wh) to mAh conversion calculator?

A watt-hours(Wh) to mAh calculator is basically an algorithm built to convert Wh to mAh and vice versa. However, to covert one of these two to the other, you need to know the nominal voltage of the battery. In a situation where you are given the capacity of the battery in watt-hours and you want to convert them to milliamp-hours, you need to know the rated voltage of that battery.

Here is the formula used by the watt-hour(Wh) to mAh calculator to do the conversions

(Wh)*1000/(V) =(mAh)

In the above formula; Wh stands for Watt-hours, V stands for voltage and mAh stands for milliamp-hours. The Wh are multiplied by 1000 in order to convert the Amps to milliamps. If you don’t multiply by 1000, the resulting capacity will then be rated in Ah instead of mAh.

For example, if we have a battery with 90Wh with a rated voltage of 5V. We can convert this to mAh using the above formula

The capacity in mAh will be 90*1000/5= 18,000mAh.

How do you convert mAh to Wh?

Converting mAh to Wh also involves using the same formula like we used above. To calculate the rated capacity of the battery in Wh from mAh, you need to know its rated voltage as well. For example, if we consider a battery with 3000mAh with a rated voltage of 6V, the capacity in Wh will be calculated as follows;

(Wh) = (mAh)*V/1000

So the capacity will be = 3000*6/1000= 30Wh

How do you use 100wh to mah calculator properly?

Like we have seen above, converting the rated battery capacity from mAh to Wh or vice versa requires to have the voltage already known. But for most Lithium-ion batteries, their rated voltage is always common. So in situations where you don’t have an idea about the rated voltage of the battery, you can use the standard nominal values of the batteries.

For instance, most of the smartphone batteries have a nominal voltage of 3.7V. For the case of Laptops, the rated voltage for the batteries is either 11.1V or 14.4V depending on the laptop and battery manufacturer. So while converting the battery capacities of laptops from mAh to Wh and vice versa, you can check the nominal voltage rating off the internet.

But if you have access to the battery especially for Laptops with removable batteries, you can read the rated voltage of the battery from the sticker or the writing on the battery. They normally contain nominal voltage and the battery capacity.

Final thoughts

Like we have seen above, the capacity of lithium batteries used in the electronic devices we use are normally presented in either Wh or mAh. If you have a need to convert the value of the capacity from one unit to another, you will need to know the nominal voltage of the battery. With the nominal voltage and the capacity in either Wh or mAh, you can convert to any of the two units using the above formulae or the online mAh to Wh calculators.

Another important thing to note is that the power rating of the adapters is not the same as the battery rating. This is because, for the charger to be able to the charge the battery, its voltage should be slightly higher than that of the battery. If it is made to be the same, then the battery may not fully charge.

For instance, the maximum voltage for Li-ion batteries used in smartphones is around 4.3V. That is why the adapters used to charge smartphone batteries always have 5V. The current of the adapters normally ranges from 1A to 9A in order to increase the power. But the voltage is always 5V.