Great work! Ocoopa needs to update their description. They say they use "a 21700", which led me to believe one cell. I knew that it could not be 10,000 Mah if it was one cell because there is not a 21700 beyond 5000, (that I know of.) This video shows they're being honest.. which is what I was looking for. Thank you!

Great to see the inside and that they are using 5000MAh 21700 cells. It appears as though those cells are connected in series? If so, it does not double their capacity (to result in 10,000 MAh capacity), rather it doubles the nominal output voltage of the battery pack to result in a nominal 7.2V rating, and the capacity remains at 5,000MAh. Still a nominal energy storage potential of 36Wh is very respectable for an electronic handwarmer. Thanks for doing this.

Wow, you are amazing

Good job, Carry on!

I want to know if that heat affects battery life?cuz heat destroys batteries

Mine just started powering on and running for 1-3 minutes, then shutting off. It is fully charged, is 2 years old as well. I wonder if it is an issue with the batteries being dead or something else. Guess it's time to open it and see.

What type of batteries are those? 21700? Or just 18650?

Unfortunately Ocoopa customer service has gone downhill since then. When I try to contact them, they don't answer. It's really a poorly made product, with no customer support.