Lightest functional solar/battery combination for charging on the go

[Niels C]

It seems like the posts on this are all a bit old, so what does people use these days for charging iphones?

For thru-hiking?

Anyone know of a good setup for a couple?

All the best Niels

[Nick Gatel]

https://www.rei.com/blog/camp/how-to-pack-for-a-pacific-crest-trail-thru-hike

How to charge it? Lots of people use solar chargers, and there are a lot of complaints about them. Instead, pack a portable charger with four or five charges (remember to get one that charges quickly in town—you don’t want to have to wait eight hours to charge up your device).

According to the PCT 2016 Survey Gear Guide, people wished they got rid of their solar charger much earlier on the trail (i.e., they wished they hadn’t brought it to begin with). Other luxury items they ditched? Extra clothing (base layers, shirts, town clothes, sleeping clothes, extra socks and underwear), camp shoes, umbrella, stove, Sawyer MINI, towel and books. Think twice before bringing the above.

[Bob Shuff]

Also interested in specific successes or fails.  Maybe most thru-hikers will find an outlet often enough to just get a bigger battery. The limited demand seems to have slowed the progress of this technology overall – solar companies seem to be more focused on larger scale solutions.

I’m headed to Philmont in July and will be on trail for 11 days without the chance of an outlet to recharge.  I may try a couple before finalizing.  I’m convinced for multiple reasons that a separate solar panel and battery is better than an integrated version.

My goal is to get max power into the battery during the hours/daylight you have, then I can use the battery to charge my phone/etc. at leisure during the night or when I’m hiking.  Many batteries focus on a quick charge to the phone, not to the battery itself.

I’m interested in Powerfilm, Suntactics and Renogy for panels.  Goal Zero, Biolite and Anker are the better known options, but heavier overall.  Despite wanting a separate solution, the Powerfilm Lightsaver is worth a look.  Biolite has an integrated option as well.

[john hansford]

I have a suntactics 5. A wire broke across the hinge, making the whole thing useless. I am still waiting for a reply as to how best to fix this.

[Niels C]

I´ve been looking at the powerfilm lightsaver, and the powerfilm lightsaver max (with a 18000mah integrated battery) since we will going two persons (in europe) and will use our phones extensively, for route planning, gps, weather and so, since we don´t have a specific route planned. I just wish there was something in between, 24 oz just seems overkill, (but for two it could be ok) and the price tag is insane. But, supposably it charges in cloudy weather which is important since we will be starting in april, in mostly humid cloudy weather. Also the syntactics max charges full in just 3 hours from wall.

I´m torn between that and the suntactics s5 with a anker 20000.

Any other ideas?

[Bob Shuff]

I contacted one of the powerfilm distributors asking them about their rollable vs foldable panels, and they suggested the foldable 10W (P15-600) or the next size up if I didn’t mind the extra weigh – which of course I do.  Here was their response:  Sorry if you are reading on your phone…
<p style=”font-weight: 400; padding-left: 30px;”>Thank you for your email.  I am going to recommend the PowerFilm F15-600 (10 watt) or F16-1200 (20 watt).  The 20 watt will add a bit more weight, but give you more charging power.</p>
<p style=”font-weight: 400; padding-left: 30px;”>PowerFilm F15-600 https://californiapc.com/Specials/PowerFilm-Solar-F15-600.html</p>
<p style=”font-weight: 400; padding-left: 30px;”>or with small portable USB power pack https://californiapc.com/Portable-Solar-Chargers/PowerFilm-Solar-Bundles/PowerFilm-Solar-F15-600-XP2KB-Bundle.html</p>
<p style=”font-weight: 400; padding-left: 30px;”>PowerFilm F16-1200 (if you get this one, we will give you an XP2000K power pack at no charge).  We have Black, Woodland, and Digital Camo in stock.  Woodland is a nice fabric for backpacking. https://californiapc.com/Portable-Solar-Chargers/PowerFilm-Solar-Foldable-Solar-Chargers/PowerFilm-Solar-F16-1200.html</p>
<p style=”font-weight: 400; padding-left: 30px;”>I would recommend also getting the RA-14 USB port that PowerFilm says works well with solar charger. https://californiapc.com/Portable-Solar-Chargers/PowerFilm-Solar-Accessories/RA-14.html</p>
<p style=”font-weight: 400; padding-left: 30px;”>All of the USB portable battery packs I have seen have built in charge regulators, so you don’t need a charge controller to charge the USB battery packs.  To answer your question about the panels that convert to USB voltage, they seem to be limited in the power they put out, usually 4 to 8 watts.  The bigger 10, 20, PowerFilm panels will give you more output and you will lose a little efficiency when converting the voltages down. The PowerFilm panels are more versatile with having a voltage capable of charging a car battery.</p>
<p style=”font-weight: 400; padding-left: 30px;”>For a backpacking trip, I would get the following:  1 x F16-1200 (or F15-600 if the extra weight is an issue), 1 x RA-14 USB port, and the XP2000K. This comes free with our bundle or we will give you one with an F16-1200 purchase.  You can also use other USB battery packs if you like another one better. https://californiapc.com/Specials/XP2000K.html</p>
<p style=”font-weight: 400;”>I’m still interested in the rollable 7W.  We all have our limit of what we are willing to pay for a lighter pack, but when the technology is there it should be considered.  I read a well thought out post by a ham radio operator and backpacker that was using rollable panels with DIY charge cabling and battery packs.  This was at least two years ago, and for the life of me I can’t locate it today.  What his solution was doing, that is hard to replicate with a USB pack is that he was charging using the ~15V from the solar panel, and had less loss by not down-converting the voltages into the battery.  Not sure if the integrated systems do this.  Efficiency = better charge when you only have limited daylight with the optimal angle in place.</p>
<p style=”font-weight: 400;”>I think the Powerfilm Lightsaver sounds good for solo if you are expecting lots of time to recharge, but I think recharging while hiking will be of questionable use, especially with a smaller panel.  I agree I wish there was something between that and the LightSaver Max – sounds more like bushcrafter than thru-hiker weights.</p>
<p style=”font-weight: 400;”>I am leaning towards the separate battery solution for two reasons.  The battery or phone you are charging should be in the shade if possible.  Also battery technology is advancing rapidly so you may want to replace the battery long before the panel.  I may still try the Suntactics 5 or 8, or the Powerfilm 7 or 10W panels before my trip this summer.  Will post results, but I don’t know when.</p>

[Niels C]

Very informative Bob, thx! How would you use the 7w powerfilm?

-I´m leaning towards the suntactics for the ability to charge a larger battery without the weight penalty.

The 10 powerfilm setup is 15 oz, with a succesfull charge the battery (2000mAh) will charge a smartphone once.

For the same weight i can have the suntactics s5 (7oz) and anker battery 10000mAh (9oz).

The primary reason to go for the powerfilm as i see it is its ability to charge in clouded weather, but i can’t find anything on it´s real world performance. If it is able to charge a smartphone once pr day by strapping it to the pack, even in clouded weather, i would go for it, since it would heavily reduce the time needed in town, in case of no sunshine for extended periods (which is very common in scandinavia..).

I really wish they would make a powerfilm with a 10000mAh battery at around 15oz:)

Best

[Niels C]

One thing i do like about the lightsaver max is that they say ou can fully charge the 18000mAh battery in 3 hours. A 20000 anker battery takes 12 hours to charge, or am i missing something?

Best

[Bob Shuff]

You may have read PowerFilm’s technology page on this here:  http://www.powerfilmsolar.com/about/technology/.  It should work better than a monocrystaline in low light, but if it’s only a trickle of charge it won’t really matter.

Will it charge while riding on a backpack?  I doubt it will be significant.  I know Stick (according to his blog) said he is planning to take a Suntactics 5W on his JMT NoBo hike, and mentioned that his back will be to the sun more than SoBo hikers.  That’s true, and I think he’s right on that the JMT probably lends it self to this with bright sun (especially morning) and minimal shade.  You may get more during a break with a stable aimed solar panel than all the time riding on your backback between them.

AT – probably a different story.  I’m not a thru hiker, just and EE that likes gear and loves to hike, currently with my son’s scout troop.

My take is to get the biggest solar panel you are willing to carry, and enough battery capacity for 2-3 days at 80% efficiency.  I agree if Powerfilm put those together into an in-between LightSaver, say 7 W  rollable panel and 10 Ah battery it would be a winner.

[Bob Shuff]

Re: LightSaver Max charging.  They say they can pull a charge in at 12V so it’s probably a custom charger – not a USB power brick.  The batteries may be configured to accept the charge at that voltage so that it’s also more efficient and therefore faster.  The panel can output 15.4V (open circuit), but probably drops to around 12V with the battery load.

Some USB power bricks and battery packs can now charge up to 3A (or 15W), so you can get a better charge rate if you get the latest.  I think Qualcomm Quick Charge 3.0 is pretty new.  I’m not up to speed on USB-C rates or battery packs that support them, but that’s my point about waiting as long as possible to get your next battery pack.  There will be something better available 2 months from now.

Whether you are charging from the sun or from the wall plug the faster you charge the battery pack the better.  You can charge your phone from that battery pack at night or as you hike down the trail.

[Valerie E]

I did a PCT section in 2016, during which we had a 10-day period with no town visits (one on-trail resupply). I brought a Suntactics 5 plus a small “lipstick”-style battery for use with my finicky iPhone.

We had lots of sun, and the set-up worked beautifully…but I’m not sure it’s necessary for those who will have access to electricity more regularly. For more “normal” 3-6 day periods between resupply, I usually take an Anker 10k or 13k, which keeps everything humming (InReach, iPhone, Steripen, iPod, headlamp).

[Megan P]

Any update on this?  Anyone purchased anything?

I had a SolarMonkey Adventurer on my JMT hike and LOVED it.  It would fully charge the battery EVERY DAY while hiking.  My only issue is the battery was only 3200MaH.  The fact that is recharged fully everyday make it so I could fully charge my camera and charge 75% of my iphone which was more then enough for a day of use.

I would love to get one with a bigger battery but I’m having a hard time finding any information on the ones that are out there.

[Bob Shuff]

I picked up a gear swap Suntactics sCharger-5, and will test it this weekend.  Stick posted and made a video about this for his upcoming JMT hike.  He’s also reported getting the expected 5W from the USB port to a separate battery.  Other hikers have given this one positive reviews.  It’s smaller than I pictured it from photos, and very stiff – seems solid.

I’m still intrigued by the powerfilm products, and the Lightsaver says it recharges it’s 3200 mAh battery in 6 hours of full sunlight.  The larger powerfilm 7W seems like a nice size, but you need a solar-to-12V and 12V-to-USB adapter, which will add weight.

[Christoph Blank]

Any updates on this? Interesting thread!

I’m looking for something similar as I’m staying at around 3000m in the alps for roughly one week (photography). This would be a nice opportunity to do field tests as I’m mostly static.

I wondered about panels to charge 18650 batteries to stay flexible. Using a Folomov A1 charger I can use them for my flashlight as well as to charge my camera.

But Powerfilm doesn’t seem to make anything outputting 5V without a buffer, so I guess it needs a regulator in between? Does anyone have a suggestion?

[Bob Shuff]

I used the Suntactics on some car camps to experiment, and it provided near 5W consistently in direct sunlight.  I also picked up a couple of cheaper panels on Amazon to experiment with:   https://www.amazon.com/gp/product/B071Z1LGFV/ref=oh_aui_search_detailpage?ie=UTF8&psc=1 and https://www.amazon.com/gp/product/B06Y655DJD/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Neither performed as well as the Suntactics – maybe 10-20% less, but they are lighter and cheaper.  My son took the $16/7.8W product on a trip to the Sierra and found it would <span style=”text-decoration: underline;”>not</span> charge most of the devices he tried.  This goes directly to the finickyness many devices have with an inconsistent or underpowered supply.  He was trying to charge phones directly, so he may have done better with a battery pack.  I think this is a good plan anytime.

For my part, I took a spare 10 A-hr battery on our Sierra trip.  I happened to get a new iPhone 8 and in airplane mode I used it 3+ days for photos an an occasional bluetooth connection to my inreach.  10 A-hr was overkill.  If I was using it for GPS maybe it would need more, but I had a map and 8 scouts with compasses.

[Ari H]

I was trying to figure out things about solar chargers and came upon this great review / tutorial.  It is long, but it brings up just about everything one needs to extend the headache that chargers provide…  :-)

It is the best info I’ve seen on the topic, so I thought I would share.  Part 2 of the video gets into all the results…

Hope this is appropriate and that someone finds it useful.

Part 1:  https://youtu.be/dIvhcY3_alY

Part 2:  https://youtu.be/nNnIZeAaaCk

 

[Mark Fowler]

My approach is based on the length of trip. I charge my headlamp (Petzl XP2), steripen Freedom and phone (used for navigation and photos)

2 days – I take no recharging gear or spare batteries

3-4 days – I take a cut down Miller charger (24g with cable) and a single 18650 3400mAh battery (46g) for 70g total.

4-6 days – I add a second battery. +46g for 116g total.

7+ days – I take a cut down 6 watt panel (88g) which reliably outputs around 800mA plus the charger and a single battery for a total of 158g.

I try not to charge while walking but if I had to I would charge the battery. Moving in and out of shade when walking stops smarter devices like the phone from charging.  I do stop for a reasonable break about 3 or 4 times a day and find that sufficient to keep everything charged up.

 

[Cameron M]

I have pushed every angle of the solar approach hard for many years, and my conclusion is that even in the best circumstances, solar rarely saves much weight, but greatly adds to the hassle factor, failure rate, and anxiety about low-sun days on 12-day trips that I just don’t enjoy. It is hard to beat the weight to power ratio of the Anker 10000, or some 6400 battery for shorter trips.

OK, if you are still curious and determined like I was, my experience is exactly like Mark, if I start a trip with every device charged, and I am sure of at least 50% sunny days, a cut-down 88g solar charger with a 18650/lipstick battery can work incredibly well, and can be an option for long thru hikes. I cut this one down, and I think there is a double capacity one out there to also consider. The branded names change, but they are all obviously the same cell, just match the exact look of this one. They claim 10 watts, expect 5 watts.

 

[NoCO-Jim]

Thanks Ari H for your post of mjlorton’s discussion/tests of Solar USB Power Banks.

Found it interesting, and just wanted to point out mjlorton’s 2015 discussion/tests of Portable USB Solar Panels:

Part 1 discussion: https://www.youtube.com/watch?v=MgRloFSeWoE

Part 2 test results: https://www.youtube.com/watch?v=nNnIZeAaaCk

Buyer beware.

[Author]

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