The smallest one is tinier than a bacterium. The largest is the size of a football field. Suffice it to say, we’re getting a charge out of the fact that February 18th is National Battery Day.

Whether it’s powering your vehicle, your laptop or even that emergency flashlight you’ve got stashed in the trunk of your car, the humble battery is a common enough item to be taken for granted. Except, of course, when it’s out of juice. And when that happens, don’t forget to check out for batteries of all sorts: automotive, marine, even charging equipment.

Did you ever wonder how many batteries it would take to power, well, you? Assuming you stick with the average American diet of 2000 calories daily, it would take about 648 AA batteries to get you through your day. Interested in where that number comes from? Here’s a link with all the science-y goodness behind that figure.