Which battery is best for your school project, given there are so many different types in stores? Today, let’s discuss their basic units of measurement. And how these relate to power capacity and what you can do with it. We’ll assume you have your project mapped out, perhaps nearing completion. Need comes first, and then the battery solution.
Which Battery Is Best By Units of Measurement
Batteries come in different sizes and shapes. Button batteries don’t get larger than a quarter. While the smallest lead-acid ones – if you find one – are size C. Then there are also special shapes like AAA cells and nine-volt rectangular ones. However, weight and density are more important.
As a rule of thumb, larger and more expensive batteries have higher power density. You may have to play this off against weight, depending on your design when deciding which battery is best. The unit of measurement is the amount of watts you get per kilogram. The chemistry inside the battery determines the actual voltage. Remember, if you connect several similar batteries in series, the voltage increments.
Power Capacity and Power Capability in Practice
A battery’s power rating on the label is nominal. The volts start falling the moment you use it, until they reach the point where the battery is flat. Power capacity refers to the amount of energy in a battery on full charge in amp-hours. In other words, how long it will last if our device draws a single amp.
However, power capability is a different matter. Capacity decreases as rate of discharge increases. If we draw more amps from a battery, it will deliver for less time. Batteries can only supply as much energy as their chemistry allows. Which battery, is hence only part of the answer. We also need to design circuits that are energy efficient. Moreover, and use them wisely too so they last for the run time of the experiment.
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