When we first started looking into the heated gloves, we found there were 2 types. Liners and gloves. All the liners we looked at ran 8 volts at most, so the highest temperature we got from them was a measly 35°C for a very short duration. So while they had nice, slim and light features, the liners didn't the punch to get us through the -30°C to -40°C weather we get from time to time in Canada. Nor did they last us very long on the high settings which we only found to be warm.
The 12v gloves we looked at were very warm, but were very bulky heavy gloves and expensive. They were designed for motorcycles and snowmobiles so finger mobility wasn't a huge concern for them. Since we wanted a glove for cyclists, we need our fingers to be nimble to hit our shifters, brakes and hold onto the bike at the same time.
So we decided to take our product development skills from electric bike components and apply it to make a 12v glove liner for cyclists. The liners offered the advantage of being able to use multiple different gloves over top of the liner. We wanted 12v because it packed the punch we needed to get through the cold weather.
We've decided to stick with the 12volt battery for a couple of reasons. At a lower voltage, the gloves simply can't very warm. So while it is easy drop the voltage down so the battery can be smaller, it means you get a glove that performs very poorly in cold weather. 12 volts is also the common battery voltage for most automotive vehicles so our gloves with the right connection can also be hooked up to your car or motorcycle.
When we first started with the gloves, we were making it to extend the cycling time for a electric bike, so we wanted to be able to hook up our gloves to the electric bike's battery. We also noticed from our testing of the motorcycle heated gloves that the battery weight was very noticeable if you needed to use your arms a lot. Moving the weight of the batteries from the wrist to a more comfortable chest pocket just seemed to be the practical thing to do. We've since added a cuff to the gloves that allows you to run which ever method you prefer.
The reason we've gone with woven carbon fiber as the heating element is that it is very thin and flexible. In our Youtube video on the evolution of the MOTIONHeat glove liners, there is a shot of the carbon fiber heating element used in our gloves. Carbon fiber pretty much resembles hair, but heats up very quickly when a current is applied through it. Yes, we were just as surprised as you when we found out how this little bit of carbon fiber could provide heat without us feeling much of any wires while wearing the gloves.