The iPhone 17 Air and Galaxy S25 Slim will be ultra-thin phones with smaller batteries - here's what it might mean for battery life.

It's already been a banner year for battery life, with newly released devices like the OnePlus 13 and OnePlus 13R producing impressive results in our battery testing. And soon, the new Galaxy S25 models from Samsung will have their chance to show just how long they can last on a charge.

Consumer electronics devices have been using lithium-ion (Li-ion) batteries for well over a decade now. Very recently, Chinese smartphone makers have switched to a new battery tech: silicon-carbon anode battery.