Within the channel, the batteries are continuously charged – and because they are loaded from the top and retrieved from the bottom, this effectively sorts them from the least to the fullest charged without any conscious effort. No need to sort, store, and keep track of your batteries. It’s like having a dispenser in the home that provides an endless supply of AA batteries! Via a unique vertical configuration, sorting and storage is integrated, automatic, and effortless. All the user has to do each time is to drop in a depleted battery from the top, and retrieve a fully charged one from below.

Source (Behance)