PowerPax offers a number of different Storacell configurations. Most photographers will probably prefer this design, which handles 12 AA cells. There are also models which hold four AA or six AAA batteries, as well as CR123 batteries. There also combo units which store AA, AAA and 9-volt cells in one caddy. The caddies are available in a range of colors, I chose orange because I thought it would stand out in my camera bag.
PowerPax Storcell caddies come in many configurations