Budget UL solar panels hack
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I've always been intrigued by solar power, and have been curious about incorporating it into my backpacking, despite some very valid arguments against it, but weight and/or price has prevented me. Now I found a 7.5w Coleman solar charger made by Sunforce (model 22007) on Amazon that very closely compares to the Nomad 7 in output, and the Suntactics 5 in dimensions, for the paltry price of $31 and some change.
I wanted to experiment with stripping one down to its lightest weight, similar to a Suntactics design, but couldn't bring myself to take a knife to my Goal Zero. So I ordered this one, and I received it today. I proceeded to disect it, BPL style, and what resulted is something I'm pretty happy with. It has all the limitations expected with a solar panel, but at under half a pound and around thirty bucks, I feel it's got great "value". There's plenty of info on the net about its performance, and although it won't output like the Suntactics will, I found my preliminary, unscientific testing out on my deck this afternoon, to prove it pretty comparable to my Nomad 7, at about half the weight. Here's some pics of the final results.
Original weight was exactly 12 ounces. The final weight is 7.3 ounces (208 grams). I'll probably add some sticky loops or something for hanging, so a couple more grams maybe, but this is the weight of the panels, the controller, and all the plastic and poly weatherproofing left intact. I don't expect much in the way of waterproofness, especially with an exposed port, but leaving all the poly coating on seemed a good idea.
Open dimensions are 11.25" x 6.75". The front of the panels each have a hard plastic covering that is divided in the center. They also came with that protective film that most lenses have, which I peeled off.
The back is one solid piece of some kind of waxy-feeling poly. Almost rubbery like.
Since these are the 12v style panels, it comes stock with a 12v cigarette lighter type plug. Very awkward and unwieldy. I just cut the cord off at separate lengths so the wires wouldn't touch. It weighed 19 grams by itself. The other end of the (somewhat oversized) control box has a single USB output jack. All my charging will be via the 5v USB port.
Where the two front panel coverings come together, I placed a slim strip of tenacious tape to prevent any future separation from the backside poly covering. Hard to see the tape, but you can make out where the plastic panels end, and the gap between them where only the backside poly acts as the hinge. Probably not necessary, but a gram of prevention and all that.
I'm still breaking into the backpacking/hiking thing, only a couple years at it and I'm just a weekender at that. So my solar usage has only been strapped across the back panniers while cycling. My Nomad works ideally under those conditions. I use it to power and charge my Android device, a rechargeable Cygolight Expilion 700, and some AA's, while in route. The open road has plenty of sunshine (weather permitting obviously). Personally, weight is less of a factor wheeling than when walking, but since my mindset has been so drastically altered by the UL paradigm, I'm really lightening there too.
Bringing solar to the trail is something I'm still working on. Weight is a key issue, and I've been wanting a Suntactics for a while, but the cost has kept me at bay. I've just been bringing extra Android batteries, and admittedly, a solar panel compared to extra batts is more of a "toy" factor than practicality, but I still think this is a good hack for the price/weight of the endeavor, even if it lags behind the Suntactics in ouput.
So anyway, this is just the panel with USB controller, similar to a Suntactic. So the "control module" in question is included in the weight, but an AA charger is extra, as is a cord for Android charging. The eneloop AA/AAA independent dual bank USB charger is 42 grams with built-cord, but requires some serious direct sun to function with the Nomad, or this panel. The Suntactics might power it better. Still on the lookout for better charger options for backpacking. A single cell low rate charger would be pretty ideal. A battery storage bank is always an option I guess, but fairly heavy. The 12v power cord I cut off weighs 19 grams, if someone wanted to leave it on.
For me personally, I would like to see some minimal performance from pack hanging, but mainly as a stop/camp/breaktime charger in direct sun. A lot depends on the device accepting the charge. My android will accept a charge by just laying this panel directly on a 30w circular fluorescent bulb. This Sunforce actually performs better than my Nomad in this low light scenario.
It compares very closely to the Nomad 7 in output. There are technical differences (which affect price), poly vs mono crystalline for example. As I say, there are side by side comparisons out there, in full sun, with meters reading output levels,etc. A lot of the comparison testing has already been done. Most reports suggest a little more efficient controller on this vs the Nomad. Perhaps someone would volunteer to sacrifice their Nomad to dissection to compare weights, but it won't be me lol
It wasn't my intention to delve into the performance aspects of this device, beyond the accepted notion that it's "good enough" and similar in function to a Nomad 7. As I initially stated, all that info is already out there. I don't even have the proper metering tools with which to accurately measure.
As a fully loaded charging kit (without backup batteries), it's 9.5 ounces as pictured with eneloop charger and dual ended (micro and mini USB) cord. It fits nicely in a generic freezer bag, which has slightly taller dimensions than a ziploc.
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