Whenever we use electricity, we want to use minimum energy to get the maximum output. This means we want maximum efficiency for electrical power being used. This efficiency is measured in terms of Power Factor. In this post we will explain what Power Factor is. We will discuss it in terms of battery chargers but it applies to other types of electrical equipment or installation as well.
Defining Power Factor
Power Factor measures the efficiency of a battery charger. In simple terms, power factor is the ratio of power drawn by the charger to the power actually utilized in charging. It is between 0 and 1 in value. The closer your Power Factor is to 1, the higher the efficiency. You will be surprised to know that all the power or amperage drawn by the charger is not used in charging the battery. So where does it go?
Components of Power Factor
Battery charger is an inductive load (as is most electrical equipment). This means that it requires an electromagnetic field to sustain itself. As we have discussed in a previous post (Ampere’s Force Law), the electromagnetic field is generated by passing electric current through a wire. So the power drawn by the charger is used to charge the battery (Working Power) as well as sustain the electromagnetic field (Reactive Power). In mathematical terms,
Power Factor = Working Power/Reactive Power
This equation tells us that Power Factor will increase with decreasing Reactive Power.
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Power Factor Correction
Power Factor can be improved by lowering amount of power consumed for generating Reactive Power. This is called Power Factor Correction. Power Factor Correction is usually done by adding capacitors to the battery charger circuit. The capacitors generate the necessary electromagnetic induction required to sustain the charger. This decreases the Reactive Power consumption.
Improving the efficiency of a battery charger has many advantages, like decreasing costs and improving charger performance. We will deal with these in detail in next post.
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