Store it on your key chain, and use it with your laptop or any USB port to charge your Apple watch.
Brad's Deals Editor Marisa,
For Prime members only, this Newdery USB Portable Apple Watch Charger drops from $15.99 to $7.99 at Amazon. Similar ones are at least $15. Check out the 17,000 reviews! It can be hooked onto a keychain and used in your car or any USB port. Choose the White color to get this price. Shipping is free with Prime or when you spend $25. Otherwise, it adds $5.99.