
http://www.ventureheat.com/p-395-aa-bat ... liner.aspx
These are powered by AA batteries, 3 per glove. I liked that for the convenience and the price. Though the liners have increased $20 in price since I bought them 2 months ago.
Also, both battery packs that I got with them, cheap plastic little things, were defective. I called them to get replacements, and they said they would send me replacements after Jan 1st, but I never got them. In the meantime, I managed to fix the battery packs, sort of, and got them working a bit. I did just call them again just now, and they promised they would be sending me two new battery packs right away.
Anyway, this morning was actually a perfect test, because one of them wasn't working. As usual in 37 degree weather, even in my thick riding gloves, my left-hand was freezing, but my right-hand, the one with the working heated glove liner was perfectly comfortable. Not too hot, and not cold at all.
Other than the problem with the battery packs (and I think I know how to fix them without soldering now... plastic was in the way of one of the batteries getting a good connection, so I think I can fix 'em without making the soldering fragile now), I have to say these things work perfectly.
When I got them, they were $40. Now they're $60. Still cheap compared to heated gloves or heated liners with fancy rechargeable batteries. Also, there is a benefit of being a liner, since there is no need to sacrifice on nice riding gloves; you can add heat to any glove (though having main glove a size a bit too large will help fit these inside).