Amazon is currently selling the Anker PowerCore 10,400mAh battery pack for just $23.99. That is good for $6 off of the regular price, or about 20-percent off. That is when you use the promo code ANKERPC4 at checkout. This makes it a great time to pick up this battery pack, since this is an all-time low price.
The PowerCore 10,400mAh is a great battery pack to pick up since it does have a 10,400mAh capacity and can fully charge your smartphone about three times (depending on your smartphone) before it needs a recharge. This one has two USB ports, so you can charge two devices simultaneously, and it also has a micro USB port for recharging it. Unfortunately, this does mean you'll likely need a second cable - if your smartphone is a USB-C smartphone. There is also no Quick Charge 3.0 here, instead, Anker has added in its PowerIQ technology, which is going to charge your device as fast as it can without overheating the phone or overcharging the battery. That is definitely a good thing for those that do want to charge their phone quickly. PowerIQ will charge at up to 2.4A, depending on the device. It will talk to your device to see how much power it can actually take before it charges it, so that it is not being overcharged.
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 $119/year (or $59/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.