My Apple remote will not function

My Apple remote will not function. I powered it overnight, but it will not work. I can use the TV, with the remote that came with it but it is cumbersome.

The remote is less than a year old and has always worked flawlessly. I forgot how I paired the remote to the TV. Perhaps that is all I need to do. I did the unplugging and waited five minutes and that did not work. Any suggestions?

Thank you!