This is a quick and easy way to make a battery pack that will allow you to use a Ryobi 18V tool for four times as long as with one battery. Sometimes a tool will die in the middle of an operation, this can mess up what you're trying to do and is dangerous in some cases. Speaking of dangerous! I get the impression that my little project is dangerous, so watch your back and don't get hurt, I believe in you.
Step 1: Layout
First of all, find a board that you like. It needs to be wide enough that it is at least an inch taller than your battery when stood up on its side. It needs to be as long as all four batteries lined up like in the picture. This is the space saving method of placing the batteries.