Amazon currently has one of Anker's newest battery packs, the PowerCore Elite 20000 on sale. It's priced at $39.99, which is good for $10 off of its regular price, and definitely makes this battery pack worth picking up right now.
This battery pack has three inputs, all of which are USB-A. So that means there's no USB-C PD available on this one. It also does not support Qualcomm's Quick Charge standard, but instead has Anker's own PowerIQ technology, which can charge your phone at up to 2.4A. Still pretty fast, in the grand scheme of things. The PowerCore Elite 20000 has a max output of 6A, or 2.4A per port. So if you are using all three ports, you are only going to get 2A out of each one. Now the interesting thing about this battery pack is the fact that it has two inputs. Allowing you to go ahead and use two micro USB cables to recharge the PowerCore Elite 20000 at the same time. This is great because it allows you to recharge it even faster. Anker quotes six hours for a complete recharge. Now if it had just a single port, that time would be closer to around 12 hours. So it's definitely noticeable, but that also means that you're going to need to use two power sources to recharge it.
This item is also eligible for Amazon Prime's free shipping. Which includes free two-day shipping, and pretty cheap (usually $3.99) next-day shipping if you need it extra fast. If you are not an Amazon Prime member yet, you can sign up for a free trial of Amazon Prime. You'll get 30 days free (if you're a student, you get 6 months), and then it's $99/year (or $49/year for students). Prime members do get a whole lot more than just free shipping though, so be sure to check out the full benefits.