With the iPhone 6 Plus, Apple was able to cram in a whole lot more battery due to the larger body. It easily gets you through a whole day. 

But for those of us that opted for the more petite iPhone 6, a battery bump was slightly less obvious. Sure, the battery increased in capacity, but the screen that needs powering also grew meaning the resultant battery life is about the same as the previous generation day-to-day. 

Battery cases have been a regular feature in the iPhone accessory market place, and for good reason. If you’re the kind of person that uses their iPhone all day or travels frequently and doesn’t always have easy access to a power outlet, you’ll know the need for a case that provides a little extra juice. While its larger brother may shirk the need for a battery case, the iPhone 6 unfortunately does not. Enter the Mugen Power battery case for iPhone 6.

Battery cases have a difficult job — they have to both be an attractive case with an appealing design that doesn’t add too much weight or bulk to your slim iPhone while packing in as much extra battery power as they can in order to be useful, too. 

The latter is perhaps the most important, so that’s where I’ll begin. Mugen Power’s battery case for iPhone 6 features a sizable 2,100mAh battery. For those of you that pay attention to device teardowns, you’ll already be aware that the iPhone 6’s battery capacity is 1,810mAh so, in theory, the Mugen Power case should be able to recharge its battery fully and still have some to spare, right? 

In my testing, I found that to be true. I’d use my phone all day and as the battery wound down toward the evening, I’d switch on the Mugen Power case and my iPhone would return to 100% soon enough. I also put the case through its paces during a recent trip that saw me setting off at 7:30am and not returning until after midnight. I still had around 30% battery left on my return. Considering I had used the phone a lot during that time for taking photos, listening to music, using Maps, I was pleased with its performance.

Using the battery feature is simple. There are four LEDs on the back indicating how full the case’s internal battery is plus an on/off button. You can click the button once to get a quick flash from the lights and see how much juice you have left or begin charging your iPhone by holding the on button. 

The case outputs power at 1A so it’s a steady pace to charge your phone at rather than a quick hit of power. What’s neat is that when the iPhone is fully charged, the case will switch off automatically to avoid wasting power. When charging, the phone and case does get a little warm, especially if you keep it in a pocket (Mugen Power does warn against this and I’d give the same advice).

It’s easy to recharge the case itself via USB although this takes a considerable amount of time with its input at 1.5A. Further, the case is capable of charging and syncing your iPhone when connected to your laptop via the provided micro-USB cable, charging your iPhone first and then the case itself. However, I found my connection was prone to cutting out mid-sync (especially once my phone hit 100%) so I couldn't rely on this as a method of syncing and resorted to using Apple's Lightning cable. 

Now, when you’re not using the battery function, the case has to perform well as a case in its own right. The Mugen Power is fairly slender for a battery case at 14.5mm thick — noticeably thicker than the iPhone itself, granted, but that’s a sacrifice battery cases must make. It does add some weight to the iPhone 6 and you’ll certainly feel it in your pocket. 

What I really liked about the design, however, is how the rear is rounded off. It feels comfortable in the hand and is reminiscent of older iPhone models in that respect. Being thick, it feels sturdy and protective. The front edge of the case is slightly raised above the screen for added protection, too. 

Along the sides you’ll see all the cutouts you’d expect for buttons and the camera with a speaker grill in the lower right. What’s unique to the Mugen Power is its enlarged, 9.5mm headphone jack hole allowing for most headphones to connect without using an adapter. Using just the Apple EarPods, I had no need for that but it might be a key feature if your headphones are a little thicker on the end.

It’s easy to get your iPhone in and out of the case with its 2-piece design — the top pops off and your iPhone slides in. The Lighting connector is perfectly aligned and I had absolutely no problems docking the phone into the case. This top portion doesn’t feel all that secure when in place (it has a slight wobble) but it never became dislodged when in use or when taking the iPhone out of my pocket as I had feared it might. 

The finish on the black version I tested was a lovely, soft touch rubber. It did pick up fingerprints fairly easily but felt great in the hand. I also tried out the silver version which is a smoother plastic and felt a bit less premium. It also picked up a couple of dings on the first day of use. 

As for price, the Mugen Power battery case for iPhone 6 will set you back around $70. This is a common price point for battery cases but you can get some with a slightly higher capacity for a similar price, although they might not be built as well. 

The Wrap-up

The Good: Doubles your iPhone 6 battery lie — perfect for those long days. Moderately slim and light design for a battery case. Feels great in hand with the rounded back and soft touch rubber. Easy to attach to your iPhone and get charging when you need it. Charge and sync functionality. Large headphone opening for those that need it.

The Bad: Can get warm while charging. Versions without the soft-touch rubber outer don’t feel as nice and are prone to scratches. Charge and sync feature is unreliable. 

The Verdict: The Mugen Power battery case for iPhone 6 is certainly capable. It can double your iPhone’s battery life and manages to do so with a design that is not unattractive. Is it the most premium battery case on the market? No, probably not. But it succeeds in getting the job done — charging your iPhone while looking and feeling pretty good. 

You can purchase Mugen Power’s iPhone 6 battery case at the company’s official store for $70 or check it out on Amazon.