My Nyko battery pack isn't charging my Wii remote. It's a few years old. How do I get it to work?

If you still have the package it came in with the warranty and the warranty hasn't expired which lasts a year you can send it back and they will replace it with a new one within a matter of a consecutive 21 hours to 21 business days depending on the mailing address and sender manufacturer. Keep in mind batteries over time as well as electronic chargers have a magnetic assembly and is possible of any deterioration of things such as corrosion, warped material, quality and or structure of thin and/or bulky materials,etc.