If you’ve ever left home with a smartphone that’s running low on battery power because you forgot to charge it in advance, one Chinese brand might have a solution for you. Vivo spin-off iQOO announced on Monday that its ultra-fast 120W charging solution is going into mass production. The company says it’s able to fully charge a 4,000 mAh battery in just 15 minutes. That’s much faster than, say, the Samsung Galaxy S20, which takes more than an hour to juice up a battery of the same size with its 25W charger. Boosting the wattage obviously speeds up the charging process, but it’s not as easy as it sounds. For one, smartphone batteries usually can’t withstand a voltage higher than 5V. To achieve a charging speed of 120W, though, iQOO says it raised the voltage to 20V (with amps set at 12A). To cut down the voltage, it diverts the power through a pair of “charge pumps” that lower it to 10V. And instead of pumping all of that into a single battery, the phone has two 2,000 mAh batteries, each taking 5V. If you don’t like waiting to charge, the wait is almost over. #FlashForward pic.twitter.com/Uq54uJEphQ — OPPO (@oppo) July 13, 2020 iQOO says its next smartphone will include 120W charging. That would make it a contender for the fastest-charging handset on the market. More details will be unveiled in August, according to the brand’s Weibo account. But competition is on the horizon. iQOO’s sister brand Oppo teased an even faster 125W charging solution that’s slated to be revealed on July 15.