The Galaxy S8 is the smartphone that brought attention back to Samsung smartphones, and that’s because the S8 finally fully embraced the edge display, with the screen wrapping around the edges on the left and right sides. Of course, the other part of the S8 is that it comes with a faster processor, a higher resolution screen and with all that comes the usage of more power.
If there’s one main flaw with not only the S8 but with most modern smartphones is that they have rather low capacity batteries for what they’re built for as most smartphones these days use up a lot of power. In this case, the Galaxy S8 has a 3,000mAh battery and that might sound like a lot of power but if you’re using its higher performance mode with it, which means faster processing and a higher resolution, the S8 will absolutely burn through that much power. Most of the time here at Charger Harbor, we would recommend that you use a portable charger, in fact, we have done a guide on the best portable chargers for the S8.
That said, a portable charger is a whole other device that you have to keep track of and that’s where battery cases come in. Battery cases are portable chargers but they have the form factor of a case, and in this guide, we’re going to be covering the best battery cases for the S8. These cases offer a good amount of power capacity that can either charge the Galaxy S8 to full power once or at least close to it.
Trianium Atomic Pro Galaxy S8 4,500mAh Battery Case
The first battery case that we have to recommend is from, Trianium. This brand is quite popular and that’s because they specialize in battery cases and this case of theirs has enough power capacity to charge the S8 to full power at least one time. You might think that this power capacity and other battery cases within this guide that have similar power capacities such as a 4,500mAh capacity might have left over power to use.
Well, that’s not true because power capacity is lost during charging and you can look more into that in our individual reviews for each of the battery cases that we mention. That said, a single full charge for a smartphone from a battery case is basically the purpose of one in the first place as they’re mini power banks.
The charging speed from most battery cases in the past for older smartphones was 5V/1.0A, and even though that was the norm back then, that’s not really the case anymore and it shouldn’t be. That’s because most smartphones these days have more power usage and so if a battery case would have a 5V/1.0A charging rate then you might be using more power than what the case can provide. Thankfully, this Trianium battery case has a 5V/1.8A charging rate and this is definitely step up from only a single amp.
Read Review for Trianium Galaxy S8 4,500mAh Battery Case
Specs of the Trianium Galaxy S8 4,500mAh Battery Case:
- Capacity: Advertised: 4,500mAh Output Capacity: 3,330mAh
- Output: 5V/1.8A
- Input: 5V/1.8A Via Micro-USB Input
- LED Power Indicators: 4 LED Dotted Power Capacity Indicators
- Size: 6.3 x 2.8 x 0.8 inches
- Weight: 4.5 Ounces
Elebase Galaxy S8 5,000mAh Battery Case
For the most part, many of the Galaxy S8 battery cases on the market have a 4,000mAh battery capacity or lower, but this Elebase battery case has higher power capacity that starts at 5,000mAh. So even if we’re considering the output capacity that can actually be used to charge your smartphone, this Elebase battery case has enough power capacity to charge the S8 to full power once and still have a little bit more left to charge the S8. Also, despite its higher power capacity, this charger has a rather slim form factor for its capacity that still matches battery cases that have as much power.
At the back of the case is where you’ll find the power button and it also doubles as the power capacity display. Where most battery cases on the market make use of four dotted LED power capacity indicators, this charger has a single LED light that changes between four different colors to indicate how much power capacity is left. It’s definitely something new and fresh.
Read Review for Elebase Galaxy S8 5,000mAh Battery Case
Specs of the Elebase Galaxy S8 5,000mAh Battery Case:
- Power Capacity: 5,000mAh | Output Capacity: 3,700mAh
- Output: 5V/1.8A
- Input:
USB-C Input: 5V/1.8A
- LED Power Indicator: Four White Power Indicators
- Size: 6 x 2.7 x 0.6 inches
- Weight: 4.5 Ounces
ZeroLemon Ultra Power 8,500mAh Galaxy S8 Battery Case
Most of the battery cases on the market have a 3,000mAh to 5,000mAh battery case, and that makes sense as battery cases are so supposed to have as much power as a mini power bank. This ZeroLemon battery case takes a totally different route with its battery case and that would be it using an 8,500mAh power capacity. A battery case that uses this much power is absolutely unheard of as it’s so much power being used and because of that, the form factor of this case is larger and heavier than most out there.
At the same time, instead of seeing the larger form factor of this case as a negative part, it’s actually quite innovative because this S8 ZeroLemon battery case is perfect for those that want a lot of power to use with their battery case. There’s so much power to use that you can actually charge the S8 to its full power about two times. That’s something that not many other battery cases are able to do.
The charging speed of this ZeroLemon case is also quite good and that’s because it has a 5V/1.5A charging speed, and the recharge rate is faster at 5V/1.8A. Along with the higher power capacity, fast charging speeds for a battery case, a protective cover; this battery case is also able to provide syncing and recharging through the case for your S8.
Read Review for ZeroLemon 8,500mAh Galaxy S8 Battery Case
Specs of the ZeroLemon 8,500mAh Galaxy S8 Battery Case:
- Power Capacity: 8,500mAh | Output Capacity: 6,290mAh
- Output: 5V/1.8A
- Input:
USB-C Input: 5V/1.8A
- LED Power Indicator: Four White Power Indicators
- Size: 6.7 x 2.8 x 0.8 inches
- Weight: 7.1 Ounces
VProof 5,500mAh Galaxy S8 Battery Case
This VProof battery case also has quite a higher power capacity for a battery case as it starts out with 5,500mAh and with that much power you can charge your S8 and still have some power left over to use. At the same time, even with that much power this case also makes use of a slim form factor that makes it easier to have it in a pocket. At the back of the batter case, very much like the Elebase case that we’ve mentioned, this case also makes use of a single LED power capacity indicator that changes colors to tell you how much power is left.
Charging power fits the standard that we expect to charge an S8 at a noticeable speed, with the output and input charging having a 5V/1.8A charging rate.
Read Review for Galaxy S8 5,000mAh VPROOF Battery Case
Specs of the Galaxy S8 5,000mAh VPROOF Battery Case:
- Power Capacity: 5,000mAh | Output Capacity: 3,700mAh
- Output: 5V/1.8A
- Input:
USB-C Input: 5V/1.8A
- LED Power Indicator: Four White Power Indicators
- Size: 6.7 x 2.8 x 0.6 inches
- Weight: 4 Ounces
Mophie 2,950mAh S8 Battery Case
Mophie is a very popular brand when it comes to battery cases, in fact, they’re a brand that focuses heavily on these types of charging electronics and it definitely shows with their S8 model battery case. That said, the power capacity of this case is quite a lot lower than most other battery cases on the market as this one starts out with 2,950mAh and because of that, you’re not able to charge an S8 to full power. However, it will come close to a full power recharge and we think that stills count as a good amount of capacity.
The charging speed for the output and input of this case is faster than what most other cases have, as this one has a 5V/2.0A charging rate, so you’re able to charge an S8 up at a faster speed. Also, there are two ways to recharge from this Mophie battery case, one would be the USB-C input port on the case and the one method is to wirelessly recharge the case. Yes, by placing the case on a Qi wireless charging stand or pad you can recharge it.
Also, this case features priority fast charging for the S8, meaning that if you use a Quick Charge wall charger with the case’s USB-C port, the S8 will charge at a fast charging speed.
Read Review for Mophie Galaxy S8 2,950mAh Battery Case
Specs of the Mophie Galaxy S8 2,950mAh Battery Case:
- Power Capacity: 2,950mAh | Output Capacity: 2,190mAh
- Output: 5V/2.0A
- Input:
USB-C Input: 5V/2.0A
- LED Power Indicator: Four White Power Indicators
- Size: 6.3 x 2.9 x 0.7 inches
- Weight: 1.6 Ounces
Galaxy S8 Alpatronix 4,500mAh Battery Case
Alpatronix is another brand on the market that specialize heavily with battery cases and this S8 battery cases of theirs have a good amount of power capacity that can charge it to full power and still have a little more left. Alpatronix does actually mention that the case has a 120% charge for the S8 and we find that to be true when we did our review for it.
The charging speed for the S8 is going to be 5V/1.5A ad recharging the battery case through the S8 is going to be 5V/1.5A, too. Just like the Mophie battery case, this one is also able to recharge wirelessly from a wireless charger.
Read Review for Alpatronix Galaxy S8 4,500mAh Battery Case
Specs of the Alpatronix Galaxy S8 4,500mAh Battery Case:
- Power Capacity: 4,500mAh | Output Capacity: 3,330mAh
- Output: 5V/1.0A
- Input:
USB-C Input: 5V/1.5A
Wireless Recharging: 5V/1.0A
- LED Power Indicator: Four White Power Indicators
- Size: 6.2 x 2.8 x 0.6 inches
- Weight: 4.1 Ounces
CASESSARY Galaxy S8 Battery Case
Basically, all of the other battery cases within this guide have a 5V/2.0A charging speed or slower, and even though the charging speeds for most of the battery cases are actually quite good, they don’t come close to the max charging rate of the S8. The max charging speed of the S8 can only be achieved with a Quick Charge charger, and even though this CASESSARY battery doesn’t feature Quick Charge with its output, it comes relatively closer than other battery cases within this guide.
That’s because the output charging for the S8 12.6W, and just to put that into perspective, the max charging speed of the S8 is 18W. Also, the recharging is even better, as the USB-C input for the battery case has a 15W recharging speed and so you should use a Quick Charge wall charger to recharge this case at its max charging speed.
Another thing that’s a little different is that this battery case makes use of six power capacity indicators at the back, and so you have more ranges to tell how much power is left to use.
Read Review for CASESSARY Galaxy S8 4,500mAh Battery Case
Specs of the CASESSARY Galaxy S8 4,500mAh Battery Case:
- Power Capacity: 4,500mAh | Output Capacity: 3,300mAh
- Output: 9V/1.4A (12.6W)
- Input:
USB-C Input:9V/1.67A (15W)
- LED Power Indicator: Six Power Indicators
- Size: 6.2 x 2.9 x 0.7 inches
- Weight: 5.3 Ounces
PowerBear Samsung Galaxy S8 Battery Case
The final battery case that we want to recommend to use for the S8, is PowerBear’s S8. This battery case basically does everything well and is much like all the battery cases that we mentioned, but combined, but it does not have wireless charging. The power capacity is enough to charge the S8 to full power at least once and the charging speed from the battery case is 5V/1.8A. However, if you wish to charge your S8 at its max charging speed then you can use a Quick Charge wall charger to charge the S8 directly even with the PowerBear’s USB-C input port.
Recharging this power bank is also quite fast as it has a 5V/2.0A recharge rate from its USB-C port.
Read Review for PowerBear Galaxy S8 4,500mAh Battery Case
Specs of the PowerBear Galaxy S8 4,500mAh Battery Case:
- Power Capacity: 4,500mAh | Output Capacity: 3,300mAh
- Output: 5V/1.8A
- Input:
USB-C Input: 5V/2.0A
- LED Power Indicator: Four White Power Indicators
- Size: 6.4 x 2.9 x 0.7 inches
- Weight: 4.6 Ounces
Since 2016, Usman has flourished as an independent tech journalist, reveling in the evaluation of diverse tech gadgets, with a particular fondness for charging technology to ascertain product performance. Besides his journalistic endeavors, he helms the Charger Harbor YouTube channel, where he extends his tech insights to a broader audience.