 Now we're ready to look at examples of using Kirchhoff's voltage rule on batteries. Now, I'm not doing a full loop yet. I'm just looking at how the potential changes from one side to another of a battery. And as a reminder here, the higher side is the positive side of the battery and the negative terminal of the battery is going to be the lower potential side. So if you have a battery in your circuit that's oriented the other way, remember that you have to have the higher value over on this side and the lower value over here on this side. And let's make sure that gets sent to the back so that we can see all of our words. Conceptually, we know which side is the lower or higher based on the shorter or longer lines for my battery symbol, but we can actually start figuring out some numbers as well. Now, sometimes you'll have a location in your circuit which is grounded and that typically is defined as our zero voltage point. And in a lot of circuits they will actually use that negative side of the battery as your zero volt side. You can't always do that, particularly if you have more than one battery in the system that won't work. But if you do have it grounded that way, then this side would be zero volts. And then our 10 volts here means that this side is 10 volts higher and so I would end up having 10 volts over here. Similarly, if I were to work on the 5 volt battery, if I ground it on the lower side, then my higher side would be the 5 volts. So you can never think about it just in terms of left or right. You have to actually look and see which side is the lower potential side and which side is the higher potential side. Now, let's take another example here. Another couple of examples. Let's say our circuit was grounded such that the higher side was zero volts. You might initially think, wait a minute, that doesn't work, but potentials don't have to be positive values. You could actually have a negative 10 volts for the lower potential side. It's still an increase of 10 volts as I move across the battery from the negative to the positive terminal. So that works. You could even have the higher side be at 5 volts. And then we have to think, okay, what would my potential be down here at the lower end? Well, since there has to be a 10 volt difference between the two, that side would have to be at minus 5 volts. So no matter what's going on, you have to make sure that as I move over this battery, I increase by 10 volts. So let me just throw some different numbers in here. Let's say I had over here on the lower potential side of this one, that the lower potential side was at 2 volts. What value would I have to over have over here on the higher side? Well, I know it has to increase by 5, so 2 plus 5 would give me 7 volts. Or similarly, let's say I knew what was happening on this side and I had 13 volts on this side. What would I have to have down here? Well, this side has to be 5 volts lower than it, so I would subtract off the 5 volts, and that would give me 8 volts for this side. So when you move across the battery in the loop, when I eventually get to the full loop for Kirchoff's voltage rule, if I move from the negative side to the positive side of the battery, my potential has to increase by the voltage of the battery. But if I'm moving in the opposite direction from the positive terminal to the negative terminal across the battery, then the potential would have to decrease across that battery. So these are just a few examples for how the potentials might work compared to the voltages as you move across batteries as we go through a loop. We'll look at a full example of the loop in a later video.