The best battery storage case for organizing different battery sizes is the "Battery Daddy Storage System." This case is designed to hold a wide variety of battery types, including AA, AAA, C, D, 9V, and even button cell batteries, making it versatile for household needs. 
The Battery Daddy features a compact, double-sided design that maximizes storage space while maintaining a manageable size for easy handling and storage. It can hold up to 180 batteries, ensuring that you have ample space for all your battery storage needs. The clear, shatter-resistant plastic construction allows you to quickly see and access your batteries without opening the case, saving time and effort.
One of the standout features of the Battery Daddy is its built-in battery tester, which helps you quickly determine the charge level of your batteries, ensuring that you only store and use batteries that are still functional. This feature is particularly useful for preventing the frustration of inserting a dead battery into a device.
The case also includes a secure, snap-lock closure to keep batteries in place and prevent them from falling out, even if the case is dropped or jostled. The ergonomic handle makes it easy to carry, and its slim profile allows it to fit conveniently in drawers, cabinets, or on shelves.
Overall, the Battery Daddy Storage System offers a comprehensive solution for organizing and storing various battery sizes, combining functionality, durability, and convenience in one package.