Amazon has discounted the Anker PowerCore Jump Starter & Portable Battery to just $54. That's down from the original price of $79.99, but that's with the promo code ANKERJS2 at checkout. This is a great deal for a really versatile portable battery here.
This battery pack from Anker isn't a regular battery pack. As mentioned in the title, it also doubles as a battery that can jump start your car. This battery can jump start your car up to 15 times on a single charge, and it is able to jump start engines up to 2.8L. That should cover most sedans, and some smaller SUVs here. The capacity is 9000mAh, so it's not a really high capacity battery here, but it is enough to keep you going for a day or two. It's also nice to have in your car for those times that you forget to turn off the lights and kill the battery when you're at work or somewhere else. Like most regular battery packs, Anker has included a flashlight on this one, and it's quite a bit bigger and brighter, allowing you to use it when you do get stranded in the middle of the night. Jumper cables are also included here, so you don't need to worry about buying anything else, also a great thing here.
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.