Cordless power tools have come a long way since Makita's 7.6V Cordless Battery
. The increase in technology has given us more power, and longer run times. This has given us more freedom, and flexibility with our tools. Something that I can only imagine will only get better.
Technology will allow us more freedom, with more power and less weight. This post is dedicated to cordless power tool technology.
First let's start with a few definitions and some background.
Volt- The technical definition goes like this: Basic unit of electrical potential. One volt is the force required to send one ampere of electrical current through a resistance of one ohm.
Sounds like college physics all over again. Let's attempt to make simpler. Electric potential is the key phrase. Electric potential is just like any other potential, it is the ability to do something. When they talk about potential, they are talking about a difference in potential between two points. Here is an analogy that will help. Let's say you have a ramp from a table top to the ground. If you have a ball at the top of the ramp what is going to happen if you start the ball rolling down the ramp? It will go all the way to the floor right? You could say that the potential difference is the difference between the top of the ramp and the bottom of the ramp. What if you put the ramp higher? The ball is going to move faster right?
This is just like Voltage. Only voltage is the difference between CHARGES, not height. A volt is just a way to measure the difference for electricity. But it works the same way. If you have a difference in charges, it is going to cause the current to flow. So having an 18V tool means that you have 18 Volts of electric potential to power the tool. If you want more power to do your work, you need a higher voltage. Are we having fun yet?
Now that we know what voltage is we can move on to the next important concept: Amp Hours.
An amp hour is a rating that tells how much amperage is available when the battery is evenly drained over a period of 20 hours. Now, this rating represents an average over the 20 hours, so if you want to find out how many amps the battery will put out, just take the rating and divide it by 20. So obviously, the higher rating the amp hours, the higher the out put will be over a period of time.
So, now that you know the ratings for cordless power tool batteries, it will be easier to tell what is important when you buy them.