There are many different kinds of batteries used in heated socks. The first ones were DC batteries were used. But now, there are AC adapters that convert the DC to AC. So will enable you to plug the battery into any usual household socket. Currently, rechargeable batteries are in use, so you can use them many times over instead of just once. These batteries are also environmentally friendly and serve us longer.
There are heated socks fitted with heating elements made of carbon fiber and powered by lithium-ion batteries with different volts capacities. These heated socks also have battery sensors that signal when the battery should be charged. These batteries are not bulky and are very lightweight.