Heated gloves are generally battery operated and work the same as othe heated clothing. This is by running an electric current through a special wire that is embedded between the gloves outer skin and inner layer. The battery to power this is normally a rechargeable battery and allow you to even control the temperature. Some of the cheaper models dont come with rechargable batteries and offer no control on the temp. Its best to look into the heated gloves carefully as some gloves might look very dear but in the long run are better. For example better brands use multi-stranded stainless steel wire a good example of this is gerbings heated gloves compared to cheaper brands that use copper wire which i find is prone to breaking to normal metal fatique. The multi-strand steel is more flexiable and stretchable and are usually insulated with teflon which gives for a much better quality heating system in your heated gloves. So shop around and try to get the balance right of price and quality when buying your heated gloves. Okay now for the technical details the heated gloves work by using the electrical energy that is powered by the battery. This power heats a heating element that is built into the heated gloves usually in the finger tips. The heating elements generate heat by provide the heat to the gloves by providing a resistance to the flow of electricity just the way your toaster works ( dont worry the elements dont get as hot as a toaster). So when looking for heated gloves check how much heat is generated by elements which is normally give in watts and where they heat is provided. There is a great range of heated gloves on the market powered by different sized and types of batteries.
1. Standard Alkaline Batteries.
Some of the cheaper brands use alkaline batteries usually 2 or 3 AA batteries or even sometimes C or D cell batteries. Normally these offer limited heat to the gloves and over a small area.
2. Rechargeable Batteries.
Better brands and manufacturers use a rechargeable battery for example nickel metal hydride (NiMH) batteries. These give better heat output and over a larger area. Downside to these they have a limited time to them.
3. Lithium Ion Batteries.
Heated gloves that use these are a lot more expensive but are a much better heated glove as they have a lot more heat and again over a much larger area and last a lot longer. Gerbings heated gloves for example who also make heated motorcycle gloves use these as well as alot of extra features.
When im buying heated gloves i try to look for gloves with multiple power settings as well as a good battery pack with an output of 6 watts or more. becareful when checking the amount of time the batter will heat as manufacturers post times when the gloves are on the lowest power.