Solar panel

Cycle-touring, Expeditions, Adventures, Major cycle routes NOT LeJoG (see other special board)
Thehairs1970
Posts: 602
Joined: 11 Aug 2018, 9:30am

Solar panel

Post by Thehairs1970 »

Anyone bought a good solar panel they can recommend? Prefer one that does 2A output.

I'm thinking if putting one in my Christmas list.
User avatar
b1ke
Posts: 536
Joined: 30 Mar 2010, 2:17pm
Location: Brighton
Contact:

Re: Solar panel

Post by b1ke »

I've got a 15w panel made by Portapow. Has dual usb outputs. A few years old now but it's been decent. The Anker stuff also seems to get good reviews
http://www.farewellburt.wordpress.com - Europe on a Tandem....
http://www.thespokeandwords.wordpress.com - West Africa on a Tandem....
User avatar
SimonCelsa
Posts: 1230
Joined: 6 Apr 2011, 10:19pm

Re: Solar panel

Post by SimonCelsa »

User avatar
andrew_s
Posts: 5795
Joined: 7 Jan 2007, 9:29pm
Location: Gloucestershire

Re: Solar panel

Post by andrew_s »

I got a Ravpower 24W, but it's not had much use beyond testing so far.

2 A at 5 V is 10 Watts, so that's your minimum requirement.

Then account for the fact that even honest advertisers are going to quote the maximum available power, which will be with the sun more or less overhead (i.e. tropical midday), with no clouds or haze to interfere.

In the UK, the midsummer sun at noon will be about 30° off from overhead, so you'll lose some power due to having more atmosphere between the panel and the sun. Wait until after you've stopped riding, and you'll lose even more (down to getting zero about an hour and a half before sunset, I should think). Try and charge whilst riding, with the panel on the back of the bike, and the panel won't be pointing at the sun, which reduces the power available both because the panel has a smaller effective area, and because a fair bit of light will reflect off an angled shiny surface.
Then there's clouds.

Overall. I think you'd be doing well to average more than about 1/3 of the rated power on a moving on tour, and less than that if the weather is unfriendly.
User avatar
ConRAD
Posts: 761
Joined: 20 May 2010, 10:55am

Re: Solar panel

Post by ConRAD »

I’ve been testing a 20Wp solar panel well laid on the back of the bike while cycling, @latitude 45°, mid summer, noon-to-2pm, no clouds, paired onto an ideal ohmic load.
Result (instrumental): 2 hours = 4 Wh approx … that meaning an average of 2W out of a 20Wp panel. That’s it.
Image
Thehairs1970
Posts: 602
Joined: 11 Aug 2018, 9:30am

Re: Solar panel

Post by Thehairs1970 »

Some depressing data. However, I do need something. It's all very well having a battery pack but the large capacity ones take forever to charge so sitting at a campsite while it does seems a bit tedious. Any other suggestions?
User avatar
ConRAD
Posts: 761
Joined: 20 May 2010, 10:55am

Re: Solar panel

Post by ConRAD »

Thehairs1970 wrote:... battery pack but the large capacity ones take forever to charge ...


Recently introduced “fast charge powerbanks?” and emerging USB-Type C connection might be the answer.

To be said that USB-Type C is not a new USB: USB-Type C can encompass indeed already existing USB well consolidated standards such as 2.0-3.0-3.1_Gen/Gen2-PD_Power Delivery and so on so forth.
It seems so far that the “C” refers exclusively to the connector type that is
- very ROBUST whether compared to existing mini-micro type A, B, etc.
- totally REVERSIBLE, i.e. pluggable upside down with no orientation distinction
- suitable to DUAL ROLE function, capable in other words of automatically adapt voltage&current within the Power Delivery USB specs, either in the role of supplying or being supplied device.
Searching on the web it appears that either Anker and Rav already offer such new USB-Type C/PD Power Packs that, mAh/Wh apart, exhibit considerable improvements into the direction of “fast charging”.

Image

Image

Image
Image
User avatar
Sweep
Posts: 8441
Joined: 20 Oct 2011, 4:57pm
Location: London

Re: Solar panel

Post by Sweep »

Covered before in other areas possibly, but doesn't fast charging of powerbanks, like fast charging if smaller cells you are going to put in a light or whatever, bring with it accelerated battery degredation?
If so, no real gain unless you are happy to accept the trade off?
Yes, my powerbanks take 8 to 12 hours to fully charge from empty, but then so do my AAs, because I charge them slowly.
On the plus side, its my understanding (folks feel free to correct me) that modern batteries are quite tolerant of repeated "mini charges", repeated partial top ups, which means that you can do useful topping up in odd hours in pubs/cafes. A multi outlet charger handy for such stuff. If in uk, a fair few spoons now have multiple multiple usb outlets so you don't even need a charger.
Sweep
brianleach
Posts: 622
Joined: 14 Jul 2007, 2:10pm
Location: Winchester, Hants

Re: Solar panel

Post by brianleach »

I've tried all sorts of solar panels over the years with very limited results.

Consequently, and I know this is not environmentally friendly, I also take a battery charger. This uses 4 AA batteries which could be rechargeable but as my trips are usually quite short I don't usually use more than a set of 4 each trip. I vary between these two

https://www.amazon.co.uk/Powertraveller ... B00DQQLMCK

Black Diamond Moji Charging Station Lantern × 1
Psamathe
Posts: 17616
Joined: 10 Jan 2014, 8:56pm

Re: Solar panel

Post by Psamathe »

I've got Anker 21W 2-port one (https://www.amazon.co.uk/gp/product/B012VL20GW).

(Actually I've got 2 for complex reasons but only ever take one with me).

Generally I charge small battery packs, GPS, camera and iPad. iPhone X will charge but it's charging seems sensitive and the screen regularly switches on which means it's consuming more power ... so iPhone tends to get charged from a battery pack overnight (does not take much to charge it).

On tour I generally manage to keep everything (lots of electronics) fully charged but a few days of rain and things get a bit tight.

I don't bother mounting it on the bike, just use it once arrived at campsite.

If I was to have to buy a replacement I'd go for the same model.

Ian
User avatar
Tigerbiten
Posts: 2503
Joined: 29 Jun 2009, 6:49am

Re: Solar panel

Post by Tigerbiten »

On tour I use a 20w/12v panel bolted to the top of my large carry freedom trailer.
The output of this is fed through an eWerks to get 5v for charging devices/batteries.
It still wont charge anything in full shade.
But it will charge a cache battery in a light overcast even though the output maybe too low to recharge a specific device.
So on an overcast day I'll try to recharge my cache battery all day and use that to recharge my other devices.

I also use a hub dynamo for lights/sat nav charging and carry cache batteries with around 4 days worth of power.
That way I get the best of both worlds with regard of keeping things charged and can go for weeks without getting a topup off the mains unless the weather is continuously very bad.

YMMV ....... :D
User avatar
ConRAD
Posts: 761
Joined: 20 May 2010, 10:55am

Re: Solar panel

Post by ConRAD »

Sweep wrote:... covered before in other areas possibly ...

You're right but I don't remember where.
About fast charging, well, for a single cell yes it definitely means higher current.
But talking of powerpacks with possible several cells internal arrangement and charging design, "fast charging" imo shouldn't be necessarily and generally confused with "higher current" ... unless you know what's going on exactly inside the mentioned powerpacks.
Then, apart the fast charging issue I like the USB-Type C interface, definitely stronger compared to all the other ones .... and it's reversable too!!
Image
User avatar
ConRAD
Posts: 761
Joined: 20 May 2010, 10:55am

Re: Solar panel

Post by ConRAD »

ConRAD wrote:I’ve been testing a 20Wp solar panel well laid on the back of the bike while cycling, @latitude 45°, mid summer, noon-to-2pm, no clouds, paired onto an ideal ohmic load.
Result (instrumental): 2 hours = 4 Wh approx … that meaning an average of 2W out of a 20Wp panel. That’s it.

Finally I found a picture of my setup, maybe someone got better results, please explain how.

Image
Image
yutkoxpo
Posts: 423
Joined: 20 Feb 2017, 5:12pm

Re: Solar panel

Post by yutkoxpo »

I tried out a 14W 3 panel solar panel in Spain a number of years ago. Obviously the tech has improved since then.
I found that mounted on the rear of the bike gave minimal output even in bright sunshine.

However, stopped and positioned properly (and moved as necessary) it works very well.

For charging on the move there really is no better option than a hub dynamo, on the assumption you can maintain a reasonable pace. In my case about 13kmh.

Another factor to consider, panel or hub, is what you are charging. Phones, for example, can come to life & go to sleep with every change of speed/light losing a lot of the power generated.

I prefer powerbanks, but not all are created equally for charging from variable sources.

On a long tour I have both. The hub for when I'm moving, the panel for when I'm stopped. I tend to stop a lot.
User avatar
Tigerbiten
Posts: 2503
Joined: 29 Jun 2009, 6:49am

Re: Solar panel

Post by Tigerbiten »

The other thing that makes a big difference is how much stuff you're trying to keep charged.
Just a sat nav and a kindle is relatively easy in most weathers.
While a sat nav + kindle + phone + tablet + camera is virtually impossible unless you have ideal conditions.

Luck ......... :D
Post Reply