The Galaxy S8 and S8+ have pretty good battery life out of the box, but sometimes, you just need some extra juice. For those occasions, you have two options: a portable battery or a battery case. Portable batteries usually offer more power for your money, but they're also rather cumbersome. These battery cases for the S8 and S8+ are just $29.99 apiece, which erases much of the cost issue, and at 5000mAh+, they're pretty beefy as well.

Oftentimes, battery cases you see on Amazon are cheap, but fail in every other way. BrexLink's offerings look well-made, are visually clean, and have fantastic reviews. The Galaxy S8 case's capacity comes in at 5000mAh, with the S8 plus's at 5500mAh. Both have a little LED on the back that indicates how much charge there is. The charging port gets relocated right below the phone's, and is still USB-C, which is handy.

Want one? Just jump over to Amazon via our source links. Shipping is free, with one-day shipping for the S8 case and two-day for the S8+ case for Prime members. This is the lowest we've seen these cases go, so don't miss out.