Mophie Juice Pack For HTC One Review

The nightly recharge is a fact of life with most modern smartphones, and the HTC One is no different, but what if you could double your runtime and protect your expensive new toy in the process? That's what Mophie promises from the Juice Pack for the HTC One, a combination external battery and hard case that, when wrapped around your phone, should let even the most ambitious power-user escape the tyranny of the charger. All that flexibility comes at a price, however: $99.95 and a considerably larger device in your pocket. Is the Mophie Juice Pack worth the compromise? Read on for our full review.

Mophie has been making battery-cases for smartphones for years now, focusing on the iPhone and iPod touch; its line-up for Android phones is a lot smaller, with device-specific models only for the HTC One and the Samsung Galaxy S III (though the company offers generic portable batteries, too). The concept is straightforward, being a hard case that's enlarged to accommodate a rechargeable power pack, that can be used to top up the internal battery in your phone.

For the HTC One, that means a 2.88 x 6.06 x 0.67 inch soft-touch plastic sled which adds 3.12 ounces to the weight of the phone (to compare, the One alone is 2.69 x 5.41 x 0.37 inches and 5.05 ounces). Black and silver versions will eventually be offered, to match the two finishes of the One itself, though only the black Juice Pack was available in time for our review.

More on the HTC One in our full review

Inside, there's a 2,500 mAh battery, 200 mAh larger than the One's own battery, charged from a standard microUSB port on the bottom of the case. That simultaneously charges the One, too, thanks to a pass-through microUSB connection which is plugged in when you slide the phone inside. It's a snug fit, involving pulling off the Mophie's top cap, slotting the One into the groove, and gently pushing it all the way into place; once the case is closed up again, there's no wiggle or movement.

Although the sides and rear of the One are covered up, you still get access to all the ports and buttons. Pass-through controls for the power/standby key on top and the volume keys on the side are included – slightly oversized, which works well with gloved fingers, and the power button is IR-transparent so you can use the HTC TV remote control app still – and there's a hole for the headphone socket too. The cut-out is big enough for most jacks, though if you're using a set of headphones with an oversized plug, you might find the case gets in the way.

On the back, there's a big cut-out for the UltraPixel camera and LED flash, along with a hole for the rear microphone. Flanking the microUSB port on the bottom edge are four connectors for a docking station (which we didn't have to test). The only controls are a button to show battery status – using a row of four white LEDs – on the lower back of the Mophie, with a switch to turn on or off the flow of juice.

Make no mistake, once the One is in the Juice Pack you're left with a big device. It's almost comically large, in fact: the bowed back panel fills your palm, and while the soft-touch finish is pleasant to touch, the Juice Pack does make the One feel somewhat like the digital signature gadgets couriers tend to carry. If you're in the habit of dropping your phone in your front jeans pocket, or your inside jacket pocket, you'll immediately notice the difference.

It also feels like Mophie missed an opportunity to build some extra functionality into that expanse of plastic. HTC's BoomSound speakers are usefully left exposed, for instance, and so a kickstand would have been an neat addition to prop the One up for hands-free video use.

Still, the Juice Pack certainly does what it promises to. Mophie recommends waiting until your One is at around 20-percent, and then flicking the switch to take the phone back up to around 80-percent; it takes more power to recharge a completely flat battery, or to top-up a battery until it's entirely full. In our testing the Juice Pack took roughly around the same amount of time to recharge the One as the HTC adapter would.

In theory, you should be able to get a full recharge out of a single blast of the Juice Pack. In practice, following Mophie's guidelines means it's more like you're doing a couple of periodic top-ups rather than going from zero to full. Still, with judicious control of the power switch and typical use of the One, we saw runtimes just short of the Mophie's maximum 100-percent improvement.

At $99.95, the Juice Pack isn't the cheapest case or the cheapest external battery. If protection is what you're after, there are far more form-fitting soft or hard cases on the market, priced from around $10; HTC's own Double Dip Hard Shell for the One is $24.99, for instance.

Meanwhile, if you're willing to sacrifice the integration, there are portable batteries with far more capacity than the Juice Pack provides. HTC offers the External Battery Bank (BB G600), for instance, a $50 block roughly akin to an oversized Zippo, and which – with 6,000 mAh to play with – could recharge your One twice before it needed topping up itself.

Then there's the lifespan of the Juice Pack itself. Mophie rates the case for "over 500 full cycles" of 0-percent to 100-percent, after which point the battery inside "may provide less than 75-percent of the original capacity." To be fair, that's par for the course for any Li-Poly rechargeable battery, but it could mean that one day you're carrying a heavy case that doesn't really deliver in terms of a lasting charge. Whether that comes before the average two-year agreement is up, and you're already thinking of getting a new phone, will depend on how much you use it.

There are cheaper ways to protect and charge your phone. A separate case and external battery will generally provide more runtime and a more easily pocketed handset. On the flip side, the best portable battery is the one you have on you when you're running low on power, and the converged solution Mophie offers scores highly on that measure.

For some, the extra bulk the Juice Pack adds will be a deal-breaker. Certainly, it makes the One a big device, but if you're a power-user the promise of up to double the runtime is a huge advantage, and we can't really fault Mophie's design for accommodating the One's controls and features.