Double the battery life of your phone with a battery case!
The Samsung Galaxy S9 and the larger Galaxy S9+ are some of the best phones you can buy in 2018 — if you own one you know this.
With a great camera and a brilliant display, both the Galaxy S9 and S9+ make for a great digital companion when you're traveling this summer and want to document everything with photos and videos — the only thing holding you back might be battery life. Wireless charging and other battery packs are convenient, but you may want to opt for a battery case which lets you keep using your phone normally while recharging the internal battery.
Note: Usually, we'd recommend a Mophie case because they're such a popular brand for this style of case, but we cannot reasonably recommend its case model for the Galaxy S9 or S9+ given its paltry battery size (only 2070mAh) and high price ($100).
We'll start out with a slim (for a battery case) option from Alpatronix that's well reviewed on Amazon and offers a good combination of bonus battery life (4000mAh) while keeping your phone protected while keeping all the functionality of your phone intact. There's a front lip around the display to defend against screen damage when you place your phone screen down, and there's a USB-C port at the bottom that can be used for both charging and data transfer purposes.
This case also supports wireless charging using the Alpatronix wireless charger ($25) or any other Qi wireless charging pad so you can maintain the convenience of wireless charging with or without the battery case on.
Get yours for just $50 and buy with confidence knowing it's supported by a lifetime warranty and a 30-day money-back guarantee.
Also available for the Galaxy S9+ with a 4600mAh battery for $60.
ZeroLemon is another brand that's known for making some beefy battery cases, but we'll start off with their slim case option first.
Featuring a 4700mAh battery, this case is capable of providing a full charge to your Galaxy S9 and features all the protection you'd expect from a case, too. On the back is an LED indicator that used different colors to let you know how much bonus battery life you have remaining. This case also supports passthrough data transfer and charging via USB-C and will let you get way more out of your phone for a pretty reasonable price.
Get your own Slim ZeroLemon case for just $30.
Also available for the Galaxy S9+ with a larger 5700mAh battery for $30.
Battery cases are sometimes considered to be too bulky — and it's totally understandable if you think this case is way too bulky. The ZeroLemon ZeroShock case is a behemoth. It's nearly an inch thick and designed to combine a massive 8000mAh battery with a rugged phone case design that's perfect for the outdoorsy type who love to go on long hikes but also want to have your phone available for photos and videos, or for emergency situations.
With a case this big, you may be interested in the optional belt clip accessory because this case might not actually fit in your pocket.
Get this case for just $60 and know that it's backed with a one-year warranty along with a 30-day money-back guarantee.
Also available for the Galaxy S9+ with a 8000mAh battery for $60.
Finally, we'll highlight this case from Powerman that's slim at just 18 mm thick but is capable of delivering a full charge for your phone. The case supports Qualcomm Quick Charge 3.0 so you can top it up right fast, and it keeps the case bezels really slim around the edge so it's comfortable to hold in your hand. With a 4700mAh Li-Polymer battery, you'll be able to keep your phone charged throughout the day.
Get your's for just $33 knowing that it's backed by a 24-month warranty.
Also available for the Galaxy S9+ with a 5200mAh battery for $34.