Solar charging 18650 on the AT light weight hiking

[Woods Walker]

Hi everybody....I searched a lot of threads but can't find the exact answer...or at least current information. I'm looking for a light solar charging kit for 18650 batteries. Will be doing section hikes of the Appalachian trail and weight is critical.
Thanks Echo154

My preferred solar comparable lithium ion charger is the Nitecore F1. I bet my Xtar ANT would also work due to it's simple nature but have not tested it yet. But despite the prepper in me liking solar my experience from section hiking the AT is they're just extra unneeded weight. You will be covering lots of ground during the day with intermittent sun. The power of 18650 when combined with a modern headlamp means odds are you will never go through 1 in a week or more. Let's do the math on say an AT Wizard. The 30 lumen mode runs regulated (or listed as) for 48 hours. Lets ignore the second firefly which is probably good enough around camp. Normally I am beat so don't use the headlamp more than 3 hours. So we are talking about 16 days. No night hike when pushing very late ever goes past 5 hours or yea just bail off trail (if allowed) and pitch camp. Most solar panels which actually has any hope of charging within a reasonable time are around 1 lb. The average 18650 is around 1.5 ounces unless mistaken. See that I am getting at? I would pack some extra 18650s, a Nitecore F1 charger, a micro USB and lightning cable if you have an Apple to charge your phone. Also a little wall outlet as have actually seen plug in places in the most unexpected places on the AT but frankly would use those opportunities to charge your phone.

edit to add.

Google the term "Hiker's midnight" as it might help. Also here is a video of a section hike I did. There are some lights being used. Truth be told I used up 1 AA Eneloop and a Keeppower 14500 for the entire trip. The CL20 lantern wasn't needed (but nice as hiked with a buddy) and the AAs still had power. So the combined power used probably didn't even equal one 18650. Had two looooong night hikes during the outing which ate up the 14500. This was rare but we needed to cover 20 plus miles on one day so yea push on.

 

[eh4]

Sunpower cells, 5V at 5W, 4oz, 6"x10".
Hard to beat that; add the Nitecore single 18650 travel charger and you'll have your solar 18650 charging capabilities for 5-6 oz and 40-45$ cost.

https://www.amazon.com/gp/product/B01IMSJZXO/?tag=cpf0b6-20

 

[eh4]

The difference between the two strategies:
Sunpower high efficiency cells vs CIGS low efficiency cells is that the CIGS May Give more charge while hiking without direct sunlight, while the Sunpower will most certainly give Much More charge when placed optimally in direct sunlight.
Also the CIGS will be harder to break, while the Sunpower will put up with a little bending but will probably fail if you mash them with focused pressure; say tightly packed against a sharp corner, or falling into something so that they hit something hard and acute... but they're reputed to put up with a little bending and whatnot.
I'd pack a small, cheap, cut down 6"×10" bamboo cutting board myself to function as a backer for the Sunpower unit, and use it as a cutting board, writing desk, emergency firewood, or end up tossing it in a hiker box if it proved to be overweight overkill.
The two charging strategies that stand out are:
constant, ambient light charging while hiking (CIGS),
vs occasional mid day naps in the shade while leaving the Sunpower unit out in direct sunlight nearby.

... finally, back to the 5.3"×8.3" Voltaic 3.5 watt, 5 volt cell weighing 5.5oz: you could be confident that it would not break, no bamboo cutting board backer, no babying, you could probably use It as a cutting board.

 

[Illum]

Earth to Echo... if you can hear us, please reply. If you can't reply use one click for yes and two for no.

 

[eh4]

What's our consulting fee again?

 

[Timothybil]

What's our consulting fee again?

An After Action report, with examples.

 

[geokite]

And another opinion...

Been backpacking for 16 years, always anally aware of every item in my pack and it's weight. Thought of the op issue many times, but I never need to use a light very long. Maybe 30 min in the morning, then hour in the evening(max). At the end of a long hiking day, I go to sleep. I'm not playing cards, reading, etc. Food was made and consumed a couple of miles back so bears look there, not here. No light needed for dinner.

Anyway, I bring an empty H32w, no head strap, but with clip. It is for night hiking if needed. Clips onto my belt, shines right on the trail. Much better than having on your head. Battery, primary, comes from my steripen when needed.

I also bring a right angle AAA light by Maratac with one battery. A homemade headlight attachment strap, with the primary laden light is only 0.75oz.

AT had lots of resupply points, send some primaries ahead to your self in your bounce box, or shop around to find the batteries. This would dramatically cut down on the hassle and weight of having a solar panel charger on your backpack.

Steve

 

[roadkill1109]

Hi everybody....I searched a lot of threads but can't find the exact answer...or at least current information. I'm looking for a light solar charging kit for 18650 batteries. Will be doing section hikes of the Appalachian trail and weight is critical.
Thanks Echo154

These two items solve everything:

https://www.fasttech.com/products/0...er-ml-102-universal-usb-smart-charger-version

https://www.amazon.com/dp/B012YUJJM8/?tag=cpf0b6-20

You can opt to swap the Miller with an Xtar MC2 for dual 18650 charging, but you lose the ability to charge gadgets using your powered up 18650's.

hope these help.

 

[ChrisGarrett]

These two items solve everything:

https://www.fasttech.com/products/0...er-ml-102-universal-usb-smart-charger-version

https://www.amazon.com/dp/B012YUJJM8/?tag=cpf0b6-20

You can opt to swap the Miller with an Xtar MC2 for dual 18650 charging, but you lose the ability to charge gadgets using your powered up 18650's.

hope these help.

I don't think that the Anker 21w PP panel resets if the sun gets blocked, or interrupted, as one would expect hiking in a semi-wooded area, so one has to unplug the device and re-plug it back in to get whatever max current is being delivered at the time of the interruption, but I may be wrong?

The Liitokala Lii 100 & 202 are single/double bay chargers ($4/$7) that do all three voltages at 500mA and 1A, have a voltage meter and work as a serviceable power bank up to 1A.

Chris

 

[StorminMatt]

This is a simple solar charging setup I have that might work well for backpacking. It uses a Sunkingdom 5W USB panel with an Xtar MC1+ charger. It charges at around .7-.8A in full California sunshine (maybe even closer to 1A in the High Sierra), and weighs in at 6oz for everything here. There are, of course, LOTS of other panels and chargers that could be used in a similar setup, but this one is quite nice and light. Not sure how it would work in less intense East Coast sunshine. But even if you can only get .5A off the thing, that's still a decent amount of charging in a lunch break or while you are breaking camp. Not sure how well it would work on a backpack, though.

By the way, there is a newer solar panel of similar construction available these days on eBay for around $10. It is sold as a 10W panel. But even if output is only in the 5-8W range, it could still be a fairly good deal. It IS a little larger (and probably heavier) than this one, though.

 

[eh4]

StorminMatt nailed it, and the picture showing the complete system is good.
Cords are often the weak link, the shorter the better so long as you can keep the battery being charged in shade.
Two cables is one cable.
- And with those high efficiency mono crystalline cells I'd want a backer to pack it against so I didn't crack a cell while packing.
- that's probably the only significant advantage of the CIGS panels, being more durable. They are supposed to maintain efficiency in high temps better than mono, and more efficiently charge in low light conditions than mono, but the mono crystalline cells are so much more efficient to begin with that it seems doubtful that the CIGS would deliver more charge in many real world conditions.

 

[Offgridled]

My set up and it works great!
free uploadcertificity.com

 

[StorminMatt]

My set up and it works great!
free uploadcertificity.com

No doubt this panel probably charges quite a bit faster than the 5W Sunkingdom. It would probably be particularly advantageous on the East Coast vs the Western Mountains. But there IS the issue of weight and size. If you want to travel light, you just can't beat the fact that the Sunkingdom setup is small and only weighs six ounces with everything.

 

[Offgridled]

No doubt this panel probably charges quite a bit faster than the 5W Sunkingdom. It would probably be particularly advantageous on the East Coast vs the Western Mountains. But there IS the issue of weight and size. If you want to travel light, you just can't beat the fact that the Sunkingdom setup is small and only weighs six ounces with everything.

Yes I agree totally with you. I have two of these set ups for my off grid cabins in Yosemite. Backpacking would be more difficult for sure.. I've been looking at the Sunkingdom 5W after I saw your post and I'm ordering a couple for my son's. Great heads up!!

 

[eh4]

I like the idea of a compromise between the two main perspectives represented.
On the one hand there's the experience of backpackers who Don't Need a lot of light, they're moving during the day and resting at night, routinely. Many through hikers have confirmed that they only needed the most minimal illumination, with few or no battery changes over thousands of miles. Most would agree though that it would be foolish for even the most gram conscious backpacker to not at least carry some source of light, especially now that it's so light and easy to do so... There's a range from Photon Freedom to Paklite for instance.
On the other hand, between "packing your fears" and preparing for realistic contingencies, there's a great value in having the ability to produce much, much more light than you might actually need, and then there's the question of whether you would ever need to recharge or replace at all.
For me, if I have the option of a brighter light then I'll use it for extending my day in the morning and evening, and so I'll use up the battery sooner or later.

These larger, heavier solar panels are undoubtedly better for charging, but keeping the weight down is really important.
Everyone's cost/benefit "analysis" may be different, but for a certain pattern of usage, and how much adaptability is built in, there should be some optimal or very nearly optimal solution.
To me, keeping the lights and batteries under 6 oz, and keeping the sustainable recharging capabilities under 6 oz. seems on the heavy side but still near optimal. That's with a pattern of usage where days can be lengthened by several hours through the use of the light, every day, while still having battery reserves for unforeseen developments, all night hiking, etc.
- at 6 oz. A quality 5 watt solar panel should be able to fully charge a high capacity 18650 in 3-4 hours of sunlight, or in a week of hit and miss, opportunistic charging.
-a Zebralight will run nearly 30 hours on M1 level, that could be a few hours of night hiking a night every week, or 2-4 winter or summer all nighters. Rechargeable with say 3 hours of solid sunlight.

Is effectively lengthening each day for a few hours or having light all night if necessary, or even the equivalent of car headlamp for a few hours or more worth carrying an extra 3/4 pound?
Some would say absolutely not, others would be willing to carry more weight than that for those capabilities.

 

[StorminMatt]

There's also the issue of what you need vs what you want. Backpacking is NOT a paid job - you don't NEED to do it. Sure, you could save weight by hiking all day and immediately turning in for the night. But what if you want to read a book a little while before going to bed? Or even play a couple of games of Sudoku on your smartphone? Some may say that you should get over this sort of thing and just go to bed because this is what they do. But remember that you are not at work here. Ultimately, if being able to do these sorts of little things on a backpacking trip is going to make it MUCH more enjoyable (vs just doing the bare necessities in the name of saving weight), then the decision to carry a solar charging kit is going to be a judgement call on your part.

 

[eh4]

Hmm, maybe some people do get paid to backpack... new goal. ;-)

 

[eh4]

Ok, 6.5oz including charge controller, 11 watts, good reviews, the best so far I believe:
https://www.amazon.com/gp/product/B01DZN5Z9E/?tag=cpf0b6-20
I'd give it a rigid backer for protection when packing it.

I'll probably still end up messing around with the 1 oz., 1 watt, 6v CIGS panel to see if it's viable for me,
but I'm ordering one of these 6.5 oz, 10.5 watt folding Sunpower panels for sure.

Nearly 2 watts per oz.; if you can trickle charge then that's gravy, but if an hour or two of direct sunlight will do the trick then you're unlikely to need that much trickle charging capability.
Just unfold it and take a siesta around noon and let the average days average out.

 

[DarlingSoul]

I recently bought this solar panel product right exactly to what you are looking for here's the link
https://agreenorigin.com/camping-solar-panels/ it's the GGX ENERGY High-Quality 7.2W Portable Solar Charger for Mobile Phone iPhone Folding Mono Solar Panel+Foldable Solar USB Battery Charger that is now under $39.99

 

[chaosdsm]

I realize OP has probably long ago made his/her purchase, but I did get my own 'trail charging system'. Solar panel was purchased from Amazon, it's an encapuslated 10 watt 5V panel from Lixada. Charger is an Xtar SC1 capable of 2A charging.

I did a test yesterday on a drained (3.15V) 5200mAh 26650 cell from Orbtronic that I use in my Convoy L6. Started solar charging at 9AM, re-positioned the panel every 2 hours. Sky was clear till about 2:45PM when clouds started building, at that point, the charger only had one light still blinking (almost fully charged), it started to get noticeably darker outside around 4:30PM at which point I stopped the test. Cell voltage when I pulled it off charger is 4.17V as tested with a digital multi-meter.

Combined weight of solar panel, charger, & USB cable is 5.25 ounces.