Siri remote does not charge

What is the lightning cable connected to, a computer a wall outlet, a rock ?😀 Also, have you attempted other Lightning cables?

Finally, have you followed the steps in If your Apple TV remote isn’t working - Apple Support

Please explain how you have attempted to charge it, remember we cannot see what it is connected to so you need to describe that for us.

What happened when you followed the steps in the link provided? Your last thing is to contact AppleCare and explain the issue. If you are in the USA the number is 800-275-2273 , outside the USA please use AppleCare Contact Info to find the number in your corner off the planet.