® The Difference Between Volts and Amps


To be technical, an ampere is really a certain quantity of electrons (the invisible bits that actually do the moving) that pass by a given spot in the circuit in a second. Specifically, one coulomb per second.


Engineers talk about voltage in really weird terms. They rightly say that voltage is difference in potential. That is, a difference measured between two points. Thus voltage is really the energy or electrical push resulting from two points having electrical disparity. Even a battery demonstrates this. A multimeter placed on the two terminals indicates the difference between the two terminals. More accumulated energy exists at one terminal than at the other.

It may be helpful to think of amps versus volts in these terms. Amps is like the water flowing out of the faucet. As a moving thing, it is easy to monitor, and changes in flow show up quickly. Volts on the other hand changes slowly. A charging system fault will make the battery's voltage drop, but it will not show up immediately, simply because the voltage will not drop very quickly. By the way, notice the holes on the bucket? They aptly represent the loads on the battery the vehicle imposes.

It seems a lot more difficult than it should be to get would-be troubleshooters to think logically about electrical systems. That is, to actually troubleshoot instead of throwing parts at the motorcycle. I think user forums have largely created this problem, focused as they are on quick fixes. One of the many misconcepts folks labor under is the idea of checking charge to the battery in volts. Yes, it works. But it is not good practice. Not by a long sight. Think about this for a minute. When you consider the output from the battery into a horn or ignition system, what do you measure it with, and what terms do you speak in? Amps, of course. Amps is a measurement of the movement of electrical energy out of the battery. Tell me then, why all of a sudden should you, when considering the movement of electricity merely in the opposite direction, into the battery, switch to volts? Is that logical?

Mike Nixon