Solar chargers?
 

OK so I've been touring long before cell phones. I've pondered over bikecentennial maps and managed to get pretty thoroughly lost going many miles out of my way. I have naturally switched to cell phone guidance and have happily left my flashlight, camera, compass and even some maps at home. Charging is sometimes an issue though and I can't seem to find a solar charger that adds much charge to a phone. Strapping a charger to the bar bag keeps the phone working but doesn't provide much extra power even when shutting off the phone most of the day.
Has anyone found a solution? Most chargers have batteries within them which seem unnecessary if the charger would fully charge or mostly charge the phone.

2 words: size matters .



:innocent:

a iPhone 11 and two good battery packs one on a solar charger and one on the phone when needed would do a lot.

I messed around with a solar panel on a kayak trip, ... ... once. Was out of cell range the whole two week trip, the sole purpose of charging was for the GPS and headlamp (for my head at night). I had a marine band radio but only used it sparingly so did not need to charge it In the end I decided that enough spare batteries for a two week trip was less weight than the weight of the charger.

Bike touring, I rely on a dynohub (SP PV8). Lots of options for USB chargers to pair with a dynohub, I bought a Sinewave Revolution for a trip where I expected a lot of rain (Iceland) in 2016, am still using that Sinewave. And use a powerbank that will function as a pass through cache battery (Voltaic V44, that model no longer made but other sizes are available). By pass through, I mean that you can put a charge into the power bank at the same time you are drawing power out of it, most power banks it is one or the other, not both.

That said, if your bike tours are no longer than a week, a large powerbank is probably most cost effective, buy one or a couple that are big enough to last for a week if you start the week with everything charged up. But multi-week tours are where you start to need to produce your own power.

I’m an ultralighter and EDC a 4oz/5W $30 set-up that’s the equivalent output of my iPhone wall charger, and provides ~4hr screen-on runtime per 1hr of stationary cloudless sunlight. Could be doubled-up/daisy-chained for a 10W set-up plus a $20 10k mah powerbank for ~1 lb - that should be plenty for most folks. These include a USB multimeter so you know what works, and how much power is moving.

FWIW, I tend to find solar only worthwhile when charging from an outdoor stationary position on a cloudless day (eg. during lunch) you suffer a lot of inefficiencies riding through shadowing, from passing clouds, imperfect angles to sun, etc.

I was just testing my solar system today (well, yesterday - after midnight now). I was backpacking a couple weekends ago and had this along. When we were in the woods we generated a little more than 1/3 of what we used for 2 days (charging 2 phones and running an HF ham radio was 30 watt-hours, production was 13 watt hours catching the sun peeking through the trees in places).

In unshaded (though, hazy skies) sun today (direct) I got to 20 watt-hours charge in an hour 45min. That is with the panels providing 5-13 watts (in bright full sun they will do 17 watts or a tad over).

The battery is a 12Ah Bioenno LiFePO4. If you are only using it to charge a cell phone every so often every day you could probably go a week or more without needing to recharge this one. The power that was used from 2 phones charging and the ham radio was about 1/11th of the battery's capacity - over 2 days. That also says you can get by with a much smaller battery.

I like having a nominal 12v system as I have a lot of things that run off of it. I run 18650 batteries also - the charger for those is a 12v-capable charger. So since all mobile electronics, ham radios, and other chargers all run on 12v it makes sense for me. As always - your mileage may vary.

As an aside - the smaller of the 2 panel units in the picture (on the right) I have been known to drape over the bags on the bike for power on-the-go. Scraping photons at every opportunity can be important if you get stuck in a period of clouds or a rainy day. If you can move and scrape photons - all the better. Otherwise, again - it doesn't take all that long to replenish what was used by setting the panels in full sun for an hr or so. That could be your lunch stop or what ever. Logistics.


https://cimg9.ibsrv.net/gimg/bikefor...b09ecc7e39.jpg

I LOVE SOLAR... that feels good to get out of the way. My setup includes a Anker 15 watt folding power sport panel a 22 kma Ravpower storage battery and a meter (Ebay $2.99 from China with shipping). The panel has a smart 2 port output so I can charge 2 items directly, but I almost always charge the battery bank and recharge everything off it. The Ravpower has three outputs and one input. What do I charge, well the phone duh, my Olympus tough camera, Mp3 payer, headlamp, front and rear bike lights, I always have the panel deployed and connected to the storage battery. I have it angled at night to capture early AM rays and also I try to capture the last rays of the day. The rest of the day it just sucks up any sun it can whenever it can. If I am stopping for a little while like for lunch I will get the best angle I can. All in all it has never failed me. On a side note I also have a off grid camper that's total solar for the last 11 years that has everything I could need including 12v led lighting and vent fans and 120 vAC 30Amp inverter that power tools like my drill, saw, chainsaw, TV, vacuum and such. Did I say I love solar?

https://cimg9.ibsrv.net/gimg/bikefor...d51e760a01.jpg

https://cimg5.ibsrv.net/gimg/bikefor...a05f5012e0.jpg

A lot of good responses. How about Cell Phone Portable Power Banks that you plug in a AC electrical wall outlet while lodging for multiple daily USB touring phone use? I like solar battery charging while rural bicycle tour camping day & night.

I've tried solar and found that is wasn't worth the trouble, for my use cases. Viable, though. A better alternative might be a dynohub.

Personally, I've attacked the "problem" on two fronts. (1) reduce energy requirements. In practical terms it meant using a smartwatch to navigate (Garmin F5). IIRC, it is 40 times more efficient than a phone; (2) Rely on a power bank compatible with power delivery. IIRC, high performance units can absorb 30W in an hour (I believe I've seen 45W somewhere...), which translates into (roughly) one week autonomy.

At 6-8 watts of power output, dyno hubs are a very very expensive option for very very little power.

In an hour and 45 minutes I generated 20 watt-hours of solar on a hazy day. That comes out to 11.42 watts average production for that period. The combination of panels I have is capable of 17-20 watts in bright sun.

If the 6-8 watts out of a dyno hub can sustain your energy requirements then it might be worth-while for you. I just find them extraordinarily expensive for what you get.

Keep in mind, also, that storage capacity is a big factor. If you can't store what you are producing because you have a small battery and have fully charged it then when you can't generate power you have a short supply in the small battery. If you had a bigger battery you can draw from that for a longer period of time, and likewise - it will take charge while you have the means to produce power.

If you have solar power and you get stuck in a period of 2-3 days of clouds with weak production - are you going to be able to sustain on battery power? Or are you going to get 6-8 ours off your battery and it be done until you can recharge?

One idea I have is to make a smaller/lighter equivalent of a wind turbine alternator that mounts to a wheel and either the fork in the front or seat/chain stay in the rear. Have the rotor with magnets tied to the spokes and the coils of the alternator mounted to the fork or chain/seat stays (like an old style speed sensor, just a lot bigger). I have no idea on what kind of power it would produce, but the other thought is by varying the coil designs per phase it would be possible to have power at different speeds. Then if coasting down a hill, for example, switch in more coils/heavier coils to take advantage of gravity to produce more charge current. For pedaling on flat ground maybe switch in a light pair of coils so there is "some" power, but not so much it would rob you of too much pedaling effort. Lots of possibilities. A little bit of power all the time from an alternator like that would be good, but again - if it is possible to harness a lot more coasting down a hill or riding with a tail wind - wouldn't that be nice? 30-50 watts should be easily attainable. The wind turbine designs I am thinking of produce hundreds of watts - so scaling that back should be pretty easy.

This topic comes up every so often and I usually say the same thing. It all depends on your power needs and whether you do other outdoor activities that require similar power supply.

For the most part, with a large enough storage battery and frugal use, you can get by without solar or dyno hubs. But for those times when you either need a different source or want to be off the grid, solar can work. Charging from available wall sockets works but you do stand the risk of theft when left unattended for long periods such as in campground washrooms. It's a problem in national and provincial parks.

I do other activities as well as cycling, including kayaking/canoeing/paddleboarding, and hiking. While a dyno hub is one option it would only serve a part of my needs and I would still need to find an alternative source. Solar bridges all activities.

My power needs are low so solar (and a storage battery) fill the need. On tour I usually use a phone, a usb rechargeable light, and an IPOD.

Many solar units don't play well directly charging cell phones. When the sun is obscured and power dips the charge cycle may be interrupted and shut off, requiring a restart. Charging a storage battery from solar, and then the devices from the battery, avoids that issue.

This is the folding solar unit I've been using for a few years now. size and weight is acceptable and the storage battery fits into a pocket on the back so it and the cords are confined. Attaches with small micro carabiners. It is similar to this product (but not the same) but comes with a sewn in pocket to store the battery: https://www.amazon.ca/Anker-Solar-Ch...4-135149aa9081

https://live.staticflickr.com/4253/3...31abfe7e_c.jpg

A note to anyone planning on being self sufficient when bike touring, use good cables. My last tour, my powerbank was slowly going down for my first couple weeks. Then I figured out that a bad cable had gotten into my supply, changed the cable from my Sinewave USB charger to my pass through cache battery and after that I had no problems with maintaining power.

***

Solar panels are getting better every year, some day I might be a convert, but not yet.

I have measured 2.5 watts on average during exercise rides near home on my SP dynohub and Sinewave Revolution USB charger. Factor in stop lights, etc., I assume 2 watts per hour average on fairly flat ground. Hilly terrain, I cut that in half since most of the time I am going slower up hills. Touring, depends on where I am but overall I think an average would be 5 to 6 hours rolling per day and likely rolling 5 or 6 days a week. Thus, I would expect daily output to be in the range of 5 to 12 watt hours per day when rolling.

I use a 44 watt hour pass through cache battery that has several days of capacity based on my dynohub output.

And with that dynohub output and several day storage in the battery, I can get by. I have my GPS on when rolling, that is my biggest single item power draw, I think that is roughly a half watt. Phone is usually in airplane mode or off. Take lots of photos with a waterproof point and shoot camera. A headlamp for my head in the campsite. And two AAA (NiMH rechargeable) powered taillights, one typically in flash mode when rolling. Also carry a headlight for the bike, but that is mostly just in case I need it for a tunnel or a trip to the pub in the evening. I do not use the bike headlight on most of my tours.

Even though the taillights look bright after a week, i charge them up weekly to keep them bright. Other devices are charged on an as needed basis.

I prefer dynohub in part because when in the campsite, I would rather not be adjusting my panels as the sun moves, I would rather get my charging done during the day when I do not even have to think about it. A few years ago on a kayak trip when I tried solar, I was frequently having to move or adjust my panels.

I saw on a different thread that you carry a lot of HAM radio gear, now I know why your power requirements are so much bigger than mine. I can see why you need tens of watts out of your panel system where I can get by with low single digits of wattage.

Aren't dynamo hubs in the 6 volt, 1.5 to 3.0 watt range? Whats a good one for charging phones? Do LBS charge much to install one?

Found a article with some guidance and graphs called:

How To Choose The Best Dynamo Hub for Bicycle Touring and Bikepacking – CyclingAbout.com
https://www.cyclingabout.com/best-dy...g-bikepacking/

I suppose while we're at it:

NEW Dynamo Hub Power and Drag Testing: Schmidt SON vs Shutter Precision vs Shimano
https://www.cyclingabout.com/dynamo-...ision-shimano/

It is complicated, I will try to be brief.

Yes, dynohubs are in the 6v 3 watt range, but it is an alternator, fast downhills can push that higher. And if you are not using much power, the voltage can climb quite high. It produces alternating current of variable voltage and amperage depending on speed and how much current is being drawn out of it. It is not like a car alternator that has a voltage regulator, there is no regulator.

Son, SP and Shimano are the common ones.

You also need a USB charger than can convert the alternating current to direct current of a nearly constant 5 v. There are several out there, I mostly use a Sinewave Revolution. There are a couple that are also combined with headlights.

Some phones and other electronic devices are quite picky about their power supply. While you can directly plug some phones into a USB charger on a dynohub, some phones and other devices require a pass through cache batter (or buffer battery) to keep the voltage and amperage more steady when you speed up, slow down, occasionally stop, etc. Some USB chargers include such a battery, some do not.

Some people use a dynohub and USB charger to put power in a powerbank while rolling, then later in the campsite plug their phone or whatever into the powerbank to charge it. That can be the simplest way to do it.

It is most cost effective to include a dynohub in a newly built bike. Adding a dynohub later costs a lot more.

Very true. Happened to us. But advances in battery banks are changing the game.The latest generation has a 60W input capacity (!) such that you no longer need to leave your charger/battery combo unattended overnight. Assuming 25% efficiency loss, 30 mins of recharging gives you more than 20Wh, which should be more than enough to power your gps, etc. for a day.

Honestly, it baffles me that "bike tourers" would consider plugging in electronics along the route in public places left unattended to charge. If you are credit card touring where you are staying at hotels, bed & breakfasts, etc (paid for hospitality amenities in a building) where you have power available, that is one thing. To be camping it and expect to stop by a gas station, for example, every day to "plug in" - that just baffles me. Same goes for the crowd that doesn't bring cooking gear and utensils.

I suppose I can understand the "weight" aspect, if that is what it comes down to, but golly gee wiz.... Why would you want to be not only tied to public places to plug in, but deal with the risk of theft along with it?

I hesitate parking the bike with bags to run in to a store or hit the restroom at a park, let alone leave my nifty gadgets exposed elsewhere out of sight so they can "charge".

I agree with everything in your post, especially that beautiful bike you ride, but want to second this quote of yours from my personal experience. Best way I've found to use a solar panel is via a storage battery than charge devices from the battery. This sucks since one loses 15-20% of the energy each time it is put into or extracted out of a battery

While I love the thought of catching a battery full of sunshine, have to agree that a fast charging power bank seems like the best option for long tours. Smart chargers increase the charging voltage allowing an 80% charge in as little as 30 minutes. Stopping for lunch every few days should be all that is needed to stay fully charged.

Lots of people love their dyno hubs, but the expense, low power and exposed wiring make a fast charging power bank a much more attractive option. Especially since I have multiple bikes.

[QUOTE=Tourist in MSN;21698493]It is complicated, I will try to be brief.

Thank you VERY much and it does add up. I must say my portable Jackery 160 AC, DC, Solar battery charger power bank is a pretty nice option to take along with either folding bikes when it isn't below freezing. I take it the same can be said about the dynohub battery setups below freezing? I would like to swap between 20 inch bikes but have different hub widths & brake types. Once had a car used during rail trail tour camping seasons.

Wow. That's a lot of information. Thanks guys. I hit a motel once in awhile and like the storage battery solution with a small solar charger to supplement. Since I use the phone intermittently for directions I don't need very much power and portable battery packs seem like the best solution for me. I love some of the solutions for remote power though.