Wired
Squeeze More Juice Out of a Dead Battery!
Tuesday, August 18, 2026
A joule thief is an electronic circuit that extracts electrical current from batteries that have dropped below the voltage threshold of most standard devices. The circuit uses an oscillator and transformer to convert the remaining low-voltage charge into usable higher-voltage pulses. This technique has been used to power LED lights and small devices with batteries that conventional electronics would no longer recognize as functional.
Original reporting: https://www.wired.com/story/squeeze-more-juice-out-of-a-dead-battery/
