There are a lot of options out their for storing and charging iPads but many of them are too pricey for school districts/classrooms. I would love to have a cart, but it just wasn't in the budget so we had to get creative and to be honest, what I have works just as well.
We simply bought a paper organizer (literature organizer). You can get these in a variety of sizes depending on your needs. I think mine is a 72 slot organizer. I only used every 3rd spot however which makes each space a bit larger not to mention I only needed 3 of the 4 vertical rows. I use the fourth row for storage of my styluses, wired keyboard, and any other extras.
Once I got the shelves placed how I wanted them, we drilled holes through the cardboard backing so we could feed the power cords through. You can see that on the picture below if you look carefully (sorry the picture quality isn't very good). We also put self stick cable clips in each spot. As you can see they ended up not being all that useful- maybe it's just first graders. Not sure if I would spend the money to get these again or not- probably leaning towards not. Each of my iPads is numbered so I needed a way for my students to know which slot to put their iPad in. Again, I wanted to find a cost effective solution so I bought black binder clips, put colored electrical tape on the end and then simply used a Sharpie to write my numbers. I then clipped them onto the edge and flipped the handles over. Viola- easy and only cost about $2.00.
Last but not least, I needed to be able to plug the iPads in to charge. Again, we wanted to be as cost-effective as possible but also keep things organized. Our solution to this was the Belkin 12 Outlet Pivot Plug Surge Protector with 8 foot cord. We bought two of these and mounted them to the back of the paper sorter. What I love most is that the outside outlets swivel out flat which meant that I could still get this pretty close to the wall.
So, that's it. Our economical way around buying an expensive charging cart. I have now had this set up for 2 years and have had no issues with it at all. If you're looking for a cost-effective way to store and charge a class set of iPads I would highly recommend this method.