(Pocket-lint) - Mophie is well-known for making the extra battery packs for the iPhone in to which your phone slides, giving you an extended battery and a sort of semi-protective shell. Mophie used to concentrate on iPhone, because it was the biggest single market, but now of course, the Galaxy S is incredibly popular too.
And, easily the Galaxy S3's biggest problem is its battery life. An otherwise very likeable phone is hampered but a power pack that, if even slightly taxed, struggles to make it through the day. Of course, you can swap batteries out, but no one really wants to bother with such silliness. So enter the Mophie juice pack for the Galaxy S3, the solution to most of your problems.
When the juice pack has the SGS3 inserted within its walls, this is quite the formidable device. It doesn't quite double the weight of the phone, but it's not far off. And as you might predict, it adds a decent amount of weight to the device.
To get the phone in, you have to pull off the top section of the juice pack. At first, this is both hard and scary, because it feels like you might break it. In practice, this isn't much of a problem, and the whole thing is well-built, so breaking it is unlikely.
At the base, you'll see a USB charging connection, as with the standard phone, and then inside the case itself, you'll find a male connector, which fits into the Galaxy S III. It's about as simple as anything gets, but it works nicely.
One very smart part of this device, is that the USB socket acts as a passthrough. So if you need to transfer data on or off your Galaxy S, you can still do it with the juice pack attached. It would have been easy for Mophie not to include this, but it did, and that's a really good thing.
At the back, there's a switch, which allows you to stop the juice pack from charging your phone, and some indicator lights to tell you how full the pack is. There's a button which you press to get a reading, too. The lights are super-bright though, which is something we didn't expect.
What the doctor ordered...
...The phone doctor, at least. Because our main frustration with the SGS III has always been about the battery. And, yes, of course you can simply buy a spare but that's never an ideal solution for a number of reasons.
Here you get enough charge to double the life of your SGS III. So we don't see the juice pack as being something you keep on the phone at all times, but something you grab when you're going to be away from power, and need to be sure you have some backup power.
And this is one of the areas where it scores over a replacement battery. You don't need to charge it attached to the phone. Unless you buy a specific battery charger for a replacement battery, you're going to need to swap the one in your phone quite often - although there are solutions to this problem that are quite neat. So it's a bit more convenient, if nothing else.
Then of course, you could take into account the extra protection it will give you if you drop your phone. Mophie doesn't make any claims about this, but it's going to be better than dropping an unprotected handset on the floor.
Considering the juice pack is £80, it's pretty reasonable. You can get replacement batteries for £10 or so, and the battery and charging kit that we mentioned earlier is £30, so this isn't perhaps the cheapest option, but for convenience, we think it's justifiable.
Of course, you could just get one of Mophie's stand-alone juice packs, and carry it around with you. We've done this, and while it's great, it still lacks the convenience of this integrated case battery. You can, however, get capacities up to 6000mAh, which means you could charge the SGSIII three times, instead of just the once with this pack.
We like the battery case juice pack. It does destroy the sleek, lightweight nature of the phone, but the phone is utterly useless to us if we can't use it because the battery is flat. So our attitude is, when the phone dies, throw this case around it and you'll get through the rest of your day.
For £80, you get a nice package that's well thought-out, nicely designed and that will get you out of tight spots. It's more elegant than other solutions, and while it adds to the bulk of the phone, it's not unmanageable in the least. Especially if you've got decent-sized pockets, or a bag.