You’d need to add the weight of a micro-USB cable and possibly a couple of mini-carabiners. The 90 cm long micro-USB cable provided weights 20 additional gr.
For further specs, see the manufacturer site.
Folded view
Use case
Long distance backpacking with no access to a wall plug for an extended time. My power needs involve flight-mode Smartphone navigation and a compact photo camera taking an average of 40 pics per day. A 10 K mAh external battery is typically good for one full week of autonomy with some reasonable safety spare. It’d be only beyond that when a solar panel would start to make sense.
I’d expect to carry an external battery that I’d charge from the panel during the day, then I’d recharge my devices from the external battery during the night. It’d be possible to charge either smartphone, camera or anything else directly from the panel but it’d make it awkward to keep using the devices at the same time.
Research
Getting new gear often involves some research for options, more so in a case like this, a field where I had no background. My favorite source turned out to be Outdoor Gear Lab, namely this article on the generics of portable solar power and this . All these resources helped me find out about the different technologies, designs and products and also learn about features I wasn’t aware of that would be important for my use case. Some of the basic features should be obvious: compact, lightweight, robust, powerful enough for one device at a time. I came upon some other more subtle, tech related criteria as the Charge Interruption Recovery, i.e. the ability to resume charging after an outage, a very likely situation in the field. You don’t want to be checking constantly whether your panel is actually charging or inadvertently turned to idling.
I eventually settled on an Anker product that wasn’t part of the above mentioned review but seemed to tick all the boxes better than any other, two panels in a foldable arrangement and a 15 Watt capacity. The extra power [21 W] of the Anker model in the review seemed worthy only if meaning to charge more than one device at a time, which wasn’t my case. Feel free to correct me on this latter if not accurate.
Purchase
It’s somewhat puzzling that in these days of global markets accessible at the click of a link the actual purchase may deserve its own chapter. It’s also mildly disheartening, first world problem kind of thing, that I had settled on a model and I was happy with the choice to find out that I couldn’t actually buy it. It wasn’t actually clear to me if the 15 W model was discontinued but it seemed to be readily available in North America and a few smaller places but nowhere in Europe where only the 21 W model was. The difference between the two, some bulk and a little over 100 gr, may seem trivial but it’s not when you’re trying to get the best tool for the task and you’re counting the ounces.
I eventually got the 15 W model from an Ebay seller in Japan at a somewhat hefty price.
Overview
The PowerPort Solar Lite 2 holds two flat solar panels in a fabric housing. It folds in three, keeping the solar panels protected when folded. The third flap has a long-side-open sleeve pocket that holds a plastic box with two USB ports and a red led. The led will light every time the panels are providing power, regardless of any actual device being plugged for charging.
Unfolded view
There’s 5 cord loops sewn into the seams for secure attachment. A 90 cm long micro-USB cable is also included. The whole bunch closes with a hook & loop strip. The long-side-open sleeve pocket is exposed when the bunch is unfolded, it has a partial hook & loop closure.
Sleeve pocket, USB connectors and led
Thanks to the little mountaineer friend for helping with keeping the pocket open for the pic.
The Solar Lite doesn’t have a battery of its own. You need to charge your devices directly or use an external battery for a two-step procedure.
In use: packing
The build feels robust enough for backpacking use. The solar panels are stiff but with some minimal give that’s important for safe packing. Once folded, the panels are well protected from abrasion. I’d typically stuff the folded bunch vertically in the pack, sandwiched between the pack fabric and an unrolled foam mat, and it suffered no apparent damage.
The one element that hurts as far as packing goes is the plastic box housing the USB connectors. It’s rigid, 1.5 cm wide and it protrudes noticeably. It’s unavoidable though, you need to house the USB ports somewhere, I guess some electronics too.
In use: design
In a backpacking use case, you can expect to hang the panels somewhere in the upper section of the back-facing side of your pack. The cord loops in the peripheral seam are meant for this. I traded the small weight of two mini-carabiners for ease of deployment. There is a silly but major design flaw in this regard: according to cord loops placement, you’d hang the whole bunch with the two sections holding the solar panels above and middle, the non-panel flap at the bottom. In such arrangement, the sleeve opening in the long side of the bottom flap gets facing down. This is a very bad design. The sleeve opening has a 4 cm long hook & loop in the middle that’s not enough to secure contents, i.e. you can’t stuff anything in the pocket while in use.
Five cord loops. I’d miss another two on the right hand side corners
Ideally, you would place the external battery or any other device about to be charged in the sleeve pocket so the cable connection is held within the same space. You wouldn’t need a long cable and you wouldn’t be hiking around with visible wiring. This is not possible.
One reasonable option would be to place the device to be charged in a side pocket in the backpack. Most backpacking specific packs have them on the lower side. This would be sleek and safe enough but you’d still have a cable running between panel pocket and pack pocket. Another option and the one I used on the trip was to reverse the placement of the panels so the non-panel flap was above with the sleeve opening facing up, then I’d place the external battery within the sleeve. With the opening facing up, the 4 cm hook & loop closure mid-length along the flap pocket felt safe enough. The problem then was that there’d be no cord loops for the upper corners: I’d use the loops in the next lower section and secure the upper flap with the Y strap on the top of the pack. This would feel safe enough with the minor inconvenience that the upper flap holding my external battery would fold down to gravity every time I’d open the pack.
Non-panel flap above, sleeve pocket opening facing up
On a late October trip, with the sun rather low on the horizon, it made sense to hang the panels facing back. On a high summer trip, it’d probably be better to aim for a top of the pack placement so the panels are facing up.
In use: charging
This was the big deal, nothing of the above would matter much if the panels wouldn’t be able to charge a device in real use conditions. In late October in Spain, the sun crosses the sky at about 50 degrees in the central part of the day.
This first time experience has been positive. With clear skies and limited shade on the trail, I’d recharge a 5200 mAh external battery from 2/4 to 4/4 in about two hours. I didn’t try the panel in cloudy skies. I did go through shady sections. Whenever I took my pack off and checked, the device was still charging, even in the shade. If the charging ever stopped, it must have resumed without manual intervention.
Assessment
This is about solar in general as much as the particular model. Both were new to me.
After this initial try, I feel solar may have a place and it may be a good solution for extended autonomy needs. This is actually news to me. My feeling from other hikers’ reports throughout the years was that solar was not to be trusted, reports varied wildly from good to disaster and were often very polarized, which didn’t offer reassurance. If I took anything from this trial, it’s that now I have my own report and I know I can trust it.
On the minus side, it’s a relatively heavy and messy solution, I quite dislike having things hanging outside my pack. It remains to be seen how it behaves in low light situations.
Regarding the Anker PowerPort itself, it feels well built with the exceptions noted above. I really can’t say about the technological depths neither can I compare with any other model.
At the time of writing and the way things are shaping up for backpacking in 2021, it’s quite likely that I’ll actually need the panel again in the upcoming season. Hopefully a follow-up review will come next.
Possible improvements
All suggestions I feel I may safely contribute would address the perceived design flaws stated above: