I’ve owned cordless tools of various kinds since I was a teenager and they were always marketed by voltage. In the nineties, 9.6 volt was the big thing. Then in the 00s it was twelve volt, and eventually 24. Now it seems like the larger tools are all 40 volt and above, but not all; my chainsaw is 24 volt and cuts down small trees just fine, and my string trimmer is 40 volt and doesn’t seem to be any more powerful than the chainsaw but the battery lasts longer.
What I don’t understand is why these things seem to be growing in voltage rather than amperage, and in marketing it seems like the voltage is supposed to be a proxy for how powerful it is. I understand the larger tool needs more power but why are the cells wired in serial rather than parallel?
In: 9
One advantage of higher voltage is that conductors for the same amount of power can be smaller and kept cooler. This is one of the reasons we use super high voltages in big transmission lines. In order to get the same amount of power transmitted at a lower voltage requires that the amperage of your power line be higher. Increasing the amps would mean that power lines would have to be far thicker and would be more prone to overheating. Now this may not actually translate to any tangible benefit in something like a power tool. Using lighter weight wiring can save a bit of material cost, but the higher voltage tool is almost certainly running at a lower amperage. So the power it outputs, and therefore it’s ability to drive a screw, might not be different.
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