Forward-looking: We're still waiting for regular smartphones with battery lives that stretch into days, but the next best thing is faster charging. Those who want to juice their batteries as quickly as possible might want to check out Xiaomi's upcoming 100W charger, which boosts a phone from zero to 100 percent in just 17 minutes.

XDA-Developers spotted a video of the charger posted to the Weibo account of Lu Weibing, General Manager of Xiaomi's Redmi sub-brand. The time-lapse clip shows a device with a 4,000mAh battery using the Super Charge Turbo tech going up against an Oppo phone (3,700mAh) and the company's SuperVOOC technology.

Oppo's 50W SuperVOOC is currently the quickest charger on the market, but even it can't compete with Xiaomi's product, which takes seven minutes to hit 50 percent charge and another ten minutes to reach full capacity. In the same amount of time, the Oppo charger juiced the battery to 65 percent.

Most fast chargers take between an hour and two hours to fill a phone's battery, and SuperVOOC can do the job in just over 30 minutes.

Xiaomi's charger isn't just a concept. Lu says it will soon go into mass production, and we're likely to see it bundled with a future Xiaomi or Redmi smartphone. There's no explanation of exactly how the technology works, though, and there are questions over heat issues and the number of recharge cycles the battery will have.

Those who prefer a phone that lasts longer might want to check out Energizer's P18K. It features an 18,000mAh battery, but its bulky size seems to be putting people off buying one.