I have used the Thermocharge 6 for about a year. I posted a review about the Thermotorch recently. I bought four of Thermo products at the same time. I wanted to wait until I had used them to post reviews. So, this is two of four reviews. I live in the North and travel back to the South when I can and I primarily use it in the North. This is a hand warmer and charger. https://www.amazon.com/dp/B01GS9QDNY/?tag=survivalmonke-20 It has been a great warmer and charger. It takes a few minutes to warm up, so I turn it on 10 to 15 minutes before I want it and it gets very warm. Put in my pocket and works very well on temps at or below 0. Better above 0, Imagine that. It charges USB devices well too. The charge lasts depending on how you use it. I have not payed attention on time it lasts on my usage, I use it then charge it. It seems very durable for my usage. It is just the right size to fit in my hand. I do recommend it for both a hand warmer and a power bank. I hope this is a useful review.