Anker’s PowerCore battery packs are your favorite portable chargers, and it’s not even close. And today only, the largest of those battery packs, the PowerCore 26800 is just $42. This model doesn’t have Quick Charge, but it can keep your phone juiced up to 7 times on one charge. Plus, its dual microUSB inputs allow it to recharge twice as fast as a regular battery pack, which is important for one this massive.