Smartwatches and glasses are part of the exciting emerging class of electronics known as wearables, but, as electronics, they still need to be removed from the wearer’s body from time to time for charging.

A team of researchers from South Korea set out to create a battery that could be embedded and clothes and solar powers, allowing people to use wearable electronics for long periods of time without the need for recharging. The team says in a Nano Letters paper (subscription required) that their final battery can compete with conventional versions, even after being folded thousands of times. They also say it is inexpensive compared to competing textile batteries.

The researchers started with strands of yarn, which they then wrapped in nickel, carbon and other materials that make up a battery. Then they added lightweight solar cells.

Integrating batteries into fabric could do more than put off or eliminate charging…