What batteries to choose for heating clothes?

Question

Rechargeable batteries

I want to craft electric heating for night astronomical surveys and walks by winter. In the draft version, it will consist of 1) Battery box 2) Body warmer in the form of insoles and glove liners, possibly one on the back 3) Warmer for a photo backpack (so that the batteries in the camera work) 4) Connectors for quick connection
In this regard, there are A few questions:
1) What battery form factor should I choose? While I settled on 18650, they are easy to get and charges are common for them.
2) What capacity is needed for full heating for 2-3 hours?
3) What are heaters made of? Nichrome? Thin copper wire? Explain the pros and cons.
4) Does it make sense to heat a backpack with equipment? Will I damage my camera and lenses?
5) What diameter of connecting conductors will fit?
6) What kind of connectors to choose for connecting insoles, etc.?
Thank you. I will be glad to all comments and opinions.

Answer 1

You need to dance on the power that the heaters consume. For example, Google, at the request of "Electric insoles", gave ultrabiker.com/ochumelye-ruchki/elektrostelka-dlya ...
Then Ohm's law will help, and there will be battery capacity.
The heater is naturally nichrome - it has been tested for decades in electric stoves and irons.
Connectors - to keep the current, and it was convenient.
For example, such.

Answer 2

Based on the laws of physics and the current development of batteries, you will keep warm just by carrying the battery pack without connecting it anywhere.

Answer 3

Isn’t it easier to dress normally, say, buy a Canadian goose fur down jacket, it’s damn convenient to move in it, it weighs little, and it’s really difficult to freeze in it in 40 degrees below zero.
Well, as a standard padded jacket + wadded pants + felt boots and you will never freeze