Rating: 3 / 5
Very light, but lost points for a smaller battery capacity than competitors and for durability concerns.
And, shouldn't we really have an Electronic category in Gear Reviews at this point? Putting this in Miscellaneous seems silly.
I did a brief research of solar charging options for my iPhone. Despite previously resisting bringing any accoutrements of my daily life while hiking, I recently read (and embraced) Amy's "iPhone for Backpacking" article, found here:
On the rare occasions when I wanted a light GPS backup I really only wanted a widget to reliably give me my current location so that I could find it on the map, and chose to carry a Garmin Geko. (That said, I've actually used a GPS for this purpose exactly once in the past 15 years, in Mount Rainier National Park.) But after reading Amy's article I accepted that a modern iPhone with a GPS would perform this rare function for me while also having much further functionality- not the least as a phone, of course. It could also be my camera, since I'm not a power photographer by any means. And perhaps some day when I'm hiking more (e.g. retired) I will also get the bluetooth version of the DeLorme inReach and want to send a text or something. Games. Books. PDFs. Music. All sorts of functions.
But make no mistake- as I now hike, except for using it as a camera it will spend almost all of the time powered down.
Using Amy's power-saving tips I have gotten my power usage down to 5% per day (well, half a day, then charged it over night) while actually using the phone as a phone. I'm sure that with everything turned off I'll do much better than that. But I have aspirations to make some longer hikes someday, including an 8-day Wind River hike this summer. God willing, someday the CT or one of the triple crown.
So I want to gain some some experience with recharging options for the iPhone, and thought I'd dive in and give it a try.
Though it might make logistical sense, I didn't just want a spare battery. I like the idea of a solar charger, in case I ever for instance found myself sending resupply boxes to remote Alaskan bush villages or whatnot during a traverse of the Brooks Range. Hey, if you're going to dream, dream big, right?
I did some research- not intensive and in a somewhat uneducated manner, since I'm no engineer and am not terribly hip to things electronic. I wanted a solar cell that could charge the phone directly but also had it's own battery (which needn't be huge). I narrowed to two contenders: the Solio Bolt or the Bushnell SolarWrap Mini. The latter is unfortunately branded as a Bear Grylls (TM) product.
The Bolt claims two phone charges on a full charge, but is heavier and looks more cumbersome. I have a hard time imagining it hanging off the back of a pack. It also has a neat Apple-specific charging mode to optimize recharge time for iPhones.
But I eventually decided on the Bear Grylls sell-out product, mostly because it is the lightest option I found. It was also the cheapest option I found. It only claims one phone charge on a full charge, though, but if I am miserly with my iPhone power usage as in Amy's article I figure I can go several days between charges which gives me plenty of time to recharge the battery with solar power. I ordered one from Amazon for $36.98.
Here are what comes with the product:
For reference I wear a size 7.5 glove- the very definition of average. Note the protective end-caps on the device in my hand. They are reasonably tight, but by no means do they seem waterPROOF. Likewise, the attachment point of the PV film to the battery seems tight, but not SEALED per se. Combined, this probably makes a rolled and capped Mini reasonably able to shed a light spritz without problems, but I wouldn't leave it out in the rain.
It is clearly not remotely as bombproof as a SolarMonkey Adventurer, Goal Zero, or Nomad... but those are MUCH heavier.
A 3-foot miniUSB cable is also included. This is used to charge the Mini's battery from an external source if desired, and can serve double duty by being used to charge devices that accept miniUSB from the Mini's battery. (Obviously, this won't work for the iPhone 5, which uses a unique input jack.) There is no actual wall jack included- you will need to supply a USB compatible jack or other power source to charge like this.
Bushnell claims a device weight of 3.1oz, and I got pretty close to that but ONLY without the miniUSB cable or the end-caps:
With the accessories it's more like this:
Frankly, most battery-only backups (no solar) that I found weigh more than that. Though granted most of them claim TWO phone recharges compared to the Mini's one.
For comparison, my iPhone 5 in a protective Otter Box weighs 5.3oz.
Here it is unrolled, though the perspective is admittedly odd:
Note the hole at the top of the roll, which Bushnell says can be used to attach the device to a pack i.e. with a carabiner. I have my worries about that- it seems like the battery at the other end would swing about like a pendulum unless it is somehow secured as well. And the flexible PV roll is VERY thin- thinner than a credit card- and I worry that it might tear if it gets caught on a branch as I walk by.
Here is the battery module, with instructions:
Bushnell says that the battery is Li-ion, but they didn't list a capacity anywhere that I could see. A post that I found on Bushwalk Australia claimed that it is 2200mAh. I did find some Portuguese (or Spanish?) commercial websites that agree with this. I'm not erudite enough to know the useful lifetime of a Li-ion battery. Since the device is so inexpensive I'm forced to wonder where the shortcuts were taken, and the battery may be one. Some engineer should chime in here, if possible.
With the miniUSB end plugged into the battery and the USB plugged into a powered USB port the battery will charge. If the included cable is switched to the other side of the battery it plugs into a USB port and the miniUSB connector is available to plug into another device to charge it from the SolarWrap Mini's battery. (I had to use Apple's cable for my iPhone test, and when I did I received no error messages.)
Here is the (power input) end, with the "input" miniUSB jack and the LED that lights red when the battery is charging and green when it is fully charged:
That's all the LED does. There is no way to get an idea of how fully-charged the battery is- it just turns green when fully charged. Other reviewers have noted that if the PV roll is deployed while the device is plugged into a phone then both the phone and Mini battery will indicate that they are charging, for whatever that's worth.
Here's the other (power output) end:
I took the device from it's packaging and set it in a sunbeam coming in through my dining room window:
The big issue, of course, is that I have no idea how fully charged the battery was when I got it. But I left it there for 1.5 hours and it didn't charge fully. It's also not fully perpendicular to the sunbeam. We do get strong light here in Colorado, though.
The next day was very overcast, and I couldn't get it to charge through my window. I had to take it outside and lay it flat:
In those overcast conditions at 23F it took another 4.5 hours to fully charge. And this isn't with it swinging into and out of shadow while attached to the pack. This is pointless, I know, since I didn't know how well charged it was to begin with, but that's the data I have. See below for other reviews.
Luckily, my wife's iPhone 5 was at 75% charge, so I hooked it up. It took a bit under an hour to give the iPhone a quarter charge from 75% to 100%:
So, thus far...
Fills my perceived needs.
Can charge phone directly or from internal battery.
Can charge phone and its battery simultaneously.
Seems easier to hang off a pack than other products.
Smaller battery compared to competitors.
Probably not as durable as some competitors.
Battery lifetime questionable?
Here are some other reviews that I found (you may have to paste the addresses together):
This has been, unfortunately, a bit of a "first impressions" review because it will probably be a while before I can really put the SolarWrap Mini through it's paces in the field. I need to completely deplete the Mini's battery and check charging time using both the solar panels and the charging cable. I also need to completely deplete an iPhone battery and check how fast the Mini charges it, and if it does so completely. More will hopefully follow.
So, I've used this a bit. On my Wind River hike I went 5.5 days and still had 65% charge on my iPhone, so I didn't even need it. (Recall that I really only use my iPhone as a camera.) But one of mu partners who used his iPhone to keep a continuous GPS track used it for a recharge and it made a full recharge from 24%. But that was from the first charge on the Solar Wrap- I still have never had to recharge the thing from the solar cell in the field.