If there's one thing that annoys me about modern smartphones, it's their abysmal battery life. Remember those old Nokia bricks that had batteries that lasted for days on end? Now you're lucky if your phone's battery lasts past dinnertime with anything more than moderate usage. Fortunately, there are ways to get around these modern inconveniences, and a 20100mAh portable charger with USB-C Power Delivery is certainly one of them.Anker is one of a few companies that makes reliable portable chargers (fair disclaimer: I own an Anker PowerCore and really like mine), and right now, their PowerCore Speed 20000 PD model has dropped its price to $79.99 ($20 off) on Amazon, no coupon required.There are a few points in favor of this model in particular. For starters, it can charge and deliver power though USB-C, which should be a given for all portable chargers in 2018. On top of that, it also supports USB Power Delivery, which not only means that it can recharge much faster (it includes a 30W wall charger, and can handle 20V@1.5A, 15V@2A, 9V@3A, and 5V@3A max input), but you can also use your MacBook's charger to power it up (power banks without USB-PD will not recharge reliably on wall chargers with USB-PD). Then there's also the fact that it's rated at 24W output (that's 15V@1.6A, 9V@2.6A, and 5V@3A with PD output and 5V@2A with standard output), which means it can also do a decent job of charging your USB-C-powered laptop. Finally, it sits right on the upper limit of the maximum battery size that the FAA allows on flights, so if you're planning to bring your portable charger in your carry-on, you won't be able to take one that's much larger than this.If you're in the market for a portable charger, check out the source link below to take advantage of this discount. The deal expires on January 29th, so don't take too long to make up your mind.Source: Amazon