UKH

I'm going on a 3 month walk next year and was thinking about a solar charger to charge a mobile phone, which would only be used about once a week.  My main concerns are weight and price.  Also, can I just plug my mobile (ordinary USB) into it whilst on the move to charge?  I know nothing about panels.

Thanks, Tracy

Hi Tracy

Me and Gwen did the Lycian Way last year and took a solar battery pack and a powerbank to charge the mobile.

Worked really well for the Trailsmart app.

I'm not sure how good it would be over time but I've used the Outdoor Pro lantern off the back of my pack to charge it then my phone:

https://www.ukclimbing.com/gear/camping/lighting/luci_inflatable_solar_powe...

That said, last time I had a long distance walk to do I binned the smart phone and bought a cheap Nokia. After a week of turning it on to text home that I was okay and the odd sneaky phone call, it was still on 97% charge.

I have one of these: Solar Charger 10W Ultra Thin Silicon Solar Panel 5V USB Ports for Phone FT

from ebay. 86g, 25x14 cm cost £10. Has holes at each corner so you can thread thin cord through and attach to a rucksack at a suitable angle when walking. Adequate for getting some charge into a phone. I made it a case from thin closed cell foam to protect it when not in use,  

You could be better served by just taking a beefy power pack, recharging it at your re-stocking stops (get one that has a quick charge feature and a matching quick charge wall charger), and of course being a bit frugal with your phone usage. You might save some weight and prime hiking time that way. 

Most panels work best when stationary and directly facing the sun, a long mid-day stop... And if they get intermittently shaded (happens a lot on a backpack), they need time to "recover" or reset the device charging (the phone cuts off the charging circuitry, since it does not get enough current). In a worst case scenario (zig-zags, trees or intermittent clouds the whole day), you might not get much charge at all, as it will be just starting and stopping the circuitry all the time with the phone "buzzing" as it thinks it's being constantly plugged and unplugged.

Panels are really best just for a basecamp scenario, in my opinion. The small 1-panel 5-7W ones ("10W" is probably just marketing, sorry) would struggle to even charge a phone in anything but optimum conditions (phones need at least 2.5W to trickle charge), the 3-panel 21W ones or bigger are harder to position on a backpack and pretty heavy, and you'd probably still need to take a power pack with you anyway.

IMHO, solar charging on a backpack doesn't work that well in the real world, unless you are hiking in a flat desert with sun on your back...

Ah, I see.  I may look at the Anker 10,000 Quickcharge. I've never carried a mobile before, but being away for 3 months, I want to log onto my email every so often so Outlook doesn't delete my account!

As mentioned above, your phone will not trickle charge and neither will standard powerbanks. I know Goal Zero do powerbanks that accept a trickle charge (I imagine other panel makers will do too) so you can charge the bank while you walk and it will deal with the shade, etc., then charge the phone from the bank at night.

Although I have no experience with their panels, this company's FAQ seems to sum up the issues pretty nicely, including use on backpack and charging the phone directly:

https://www.suntactics.com/faqs

Portable solar panels need shining, costant sun at an optimum angle. If you can provide that, they can work quite well, of course 

BTW, If you get tempted by those "hybrid" solar power banks (the size of your normal power bank, with a very small solar panel on one side), just don't. Their small panel is quite useless (probably 1-3W or less), and if you "charge" it in the sun (which would probably need a week of sunshine to top up the internal battery), you are only baking that big battery inside to death...

Last, don't believe the output numbers on most of the (esp. Chinese) portable solar panels - these could be theoretical numbers (without any losses), in perfect lab conditions or even outright lies. Real world - perhaps around 50-75% of that, depending on your conditions and how much crazy their marketing felt.

I use the Anker on multi day trips. I will charge my iphone 4 times easily. I also use it to charge my GPS watch. If you are frugal with it, it should last 2 weeks but will depend on phone usage.