Measuring Battery Capacity

In this generation, battery need by people to give energy for electronic tools or machines stuff. Handphone need battery, laptop need battery, flash light need battery, motorcycle need battery, car need a battery, and so many things need a battery. Battery has energy to give power for the electronic tools and machines. With battery, people can do anything with mobile without connect to the wire of electricity.

We know we need battery, and How to measure our battery capacity. Before that, we have to know what mean of capacity battery. It’s mean amount of energy inside of battery, people call it in Ampere Hours (AH), and Watt Hours (WH).

1 A electron flow same with 6.24 x 10^18 electrons flowing through a certain point per second. We can measure battery capacity in Ampere Hours (AH). Let see the picture below, there is a battery and a circuit for measuring. Actually, we have already know the capacity of new battery without measuring the capacity. Just read from the body of battery, but.. how if our battery is already old or you just want to know the real capacity. Ok, let’s see the picture below;

Above is the circuit to measure battery capacity, R is Resistor 10 ohm / 10 Watt. It’s better if you use more than 10 Watt, depends on what battery that you meausure. If the battery aproximately more than 15 Watt, I recomended you using 20 Watt resistor. Because we flowing the current of all battery to resistor. Becareful, first, if you use resistor with low watt than your battery, I don’t suggest you measure more than 3 second. Because it will broke and heating your resistor.  Second, your multimeter range must high than your battery capacity, if not, you are broking your multimeter fuse.

If we see picture above, the battery informed 12 V 7 Ah, it’s mean the battery flow the output maximal 12 V for 7 Ampere Hours. We can measure battery life, for example battery has has 7 Ampere Hours (AH) and our load need 1 Ampere.

Battery life = Capacity (in AH) / Load (in A) = 7 AH / 1 A = 7 Hours

So, we have 7 Hours battery life.