I've previously tested it with 10 watts per hand. After 30 minutes diving in the icy water my hands were freezing significantly. In one of the dives I applied power only on one arm and saw a very large difference between the temperature of the hands. Yes, 10 watts was not enough, but it's much better than nothing.
The last model I made ​​with 18 watt carbon tape per glove and placed it as close as possible to the hands. To do this, bought sandwich insulated gloves: thin inner glove - insulator - thick outer glove. Removed the insulator - the middle layer. Then I sewn the carbon on the outside of a thin inner glove. On each glove connected the
power button. Put on top thick outer gloves, connected the wires. Power supplied from 6
lithium ion battery attached to a belt under dry suit.
I can say exactly, 18 watts is enough for ice water at any length dive.
With a carbon ribbon is easy to work, and it is easy to place in any items of equipment. The next time I'll try to make a heated vest.
