How to instore a cartridge?
What's the shelf life? How can i instore them better?
Cartridges have two years shelf life, and if your new cartridges are "several" years old they are probably beyond the shelf life. Check the warranty date on the cartridge as shown.
When buying new cartridges look for the "install by" date on the box. I would look for cartridges with at least six months remaining before the "install by" date, resulting in a year of remaining warranty.
When storing cartridges for an extended period of time keep them in a cool place and keep them upright as they would hang on a store display.