For example, run a motor or power a light bulb, for example. So this becomes very useful and we'll do many more examples using this in the future. So I already spoke about this briefly in another lecture, but I want to talk about it once more. Now, the reason that a D battery has more energy than AAA battery is not because a difference of cell voltage. In fact, the cell voltage for this guy and this guy are the same. It's 1.5
volts.