Solar charging for long distance touring

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Davidwd
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Joined: 1 Aug 2015, 7:42am

Solar charging for long distance touring

Postby Davidwd » 28 Sep 2015, 11:16am

Hi,
I have just bought the Anker 15 watt folding solar panel and it fits on top of my panniers perfectly.

The problem is when it is cloudy the panel will charge but it is not enough to switch on the charging process for my iPhone or garmin.
Does anyone know of a battery type device which would absorb the low current and then allow me to charge my devices when it is full?

Thank you

David

jacksonz
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Joined: 29 Sep 2015, 7:24am

Re: Solar charging for long distance touring

Postby jacksonz » 1 Oct 2015, 7:59am

I guess the first thing to do is make some measurements with a multimeter of the panel output under cloud. It may be the case that often the output would not be worth collecting.. Personally I don't know of any ready made devices. A lithium power bank is very useful on tour.

An interesting experiment would be to connect 4x nickle metal hydride batteries to the panel. In sun the panel would charge these batteries and provide a reserve from which you could run your Garmin?

DoctorRad
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Joined: 10 Nov 2010, 5:48pm

Re: Solar charging for long distance touring

Postby DoctorRad » 2 Oct 2015, 1:01pm

Yes, there are numerous USB batteries on the market, of which I've tried a couple in conjunction with a USB solar panel.

Panel: http://www.amazon.co.uk/dp/B00XCEXL3E (I have the 7W version now superseded by an 11W panel)
Battery 1: http://www.amazon.co.uk/dp/B00KZLXUR4 (PortaPow)
Battery 2: http://www.amazon.co.uk/dp/B00YL6EOM4 (this is second generation Zendure A5. I have the first generation A5 which is between the 2G A3 and A4 in capacity)

I tried both of these batteries with the panel during a French camping and B&B trip this summer, and everything worked pretty much as expected, though there was often a LOT of sunlight.

Both batteries have what's called 'pass-through' charging, i.e. if a device is connected to the battery at the same time as an input charge current, the battery is bypassed and the device is charged from the input. he battery will charge if the device is disconnected. They also have four LED indicators to show remaining charge and indicate when charging is taking place. In the case of the Zendure, these are very small and almost invisible in sunlight. In the case of the PortaPow, they are large, and bright; indeed prohibitively bright when I had the battery charging from the mains overnight on the other side of the room in the B&B... they could easily double as a nightlight!

The PortaPow battery has an on-off switch, allowing you to control when power is leaving the battery. However, it doesn't turn on when you first connect a device, you have to use the switch. This was useful for using LED lanterns without switches in the tent (http://www.amazon.co.uk/dp/B00RVGMKL8) but might be frustrating if you want to connect a phone or GPS to the battery and the latter is buried in a handlebar bag, for instance.

The Zendure battery had a slightly odd behaviour inasmuch as when it had been connected to the solar panel, it would only ever report 2/4 charge level until it had charged by a mains charger with >~1A output current - neither the solar panel nor a car charger would get it above 2/4 charge indication. Not sure what was going on there. The Zendure does have 'automatic start' when a device is connected

The Australian dynamo manufacturer kLite - whose lights I use - recommends Limefuel battery packs, but these aren't available so readily in the UK. They too have pass-through and no switch, but are generally cheaper the the premium/ruggedised Zendures. This is a good round-up of the market, though not all the packs are readily available in the UK:

http://thewirecutter.com/reviews/best-p ... daily-use/

Finally, for emergency back-up use, B&M Home bargains is (or at least was about six months ago) selling single-cell USB batteries for a fiver. Very small and light, but for that price they likely contain recycled laptop cells, which may be of dubious provenance. I got one to play with, and while it would accept charge and operate in pass-through mode, leaving it fully charged has resulted in it now only charging my smartphone to about 60%. As I say, it would probably be okay for an emergency back-up, but may not have enough capacity or reliability for your needs. They're now offering something a little larger for £7.99 (http://www.bmstores.co.uk/products/opti ... mah-304578) but no idea as to quality. Probably worth a try for that price though.

All of that said, a dynamo with a USB converter is likely to be a much more reliable power source than a solar panel...!

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[XAP]Bob
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Joined: 26 Sep 2008, 4:12pm

Re: Solar charging for long distance touring

Postby [XAP]Bob » 2 Oct 2015, 1:21pm

Why go solar when you have a reliable mechanical option available? A dynamo hub will give you lots of glorious power to use.

Any commercial cache battery should do what you are asking.
A shortcut has to be a challenge, otherwise it would just be the way. No situation is so dire that panic cannot make it worse.
There are two kinds of people in this world: those can extrapolate from incomplete data.

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RickH
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Joined: 5 Mar 2012, 6:39pm
Location: Horwich, Lancs.

Re: Solar charging for long distance touring

Postby RickH » 2 Oct 2015, 2:11pm

[XAP]Bob wrote:Why go solar when you have a reliable mechanical option available? A dynamo hub will give you lots of glorious power to use.

I can see it as a more viable option if you are doing a "camp several days in one place & explore before moving on" type trip - especially if the exploring has big climbs & you want to keep unladen weight down for those bits (I've contemplated doing that sort of trip in the Alps, whether I'll get round to it is a different matter :? ) - where you can leave the solar panel charging stuff while you're out on the bike (or even doing something completely different).

Rick.

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andrew_s
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Location: Gloucestershire

Re: Solar charging for long distance touring

Postby andrew_s » 2 Oct 2015, 2:19pm

[XAP]Bob wrote:Why go solar when you have a reliable mechanical option available? A dynamo hub will give you lots of glorious power to use.

I have come across someone complaining that dynamo power wasn't adequate when touring in a mountainous area.
They were going too slowly when grinding up the big hill in bottom gear to generate usable power, and they couldn't harvest enough of what was available during the short period whizzing down the other side to make up the shortfall.

Bigdummysteve
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Joined: 24 May 2015, 9:29am
Location: Oxfordshire

Re: Solar charging for long distance touring

Postby Bigdummysteve » 9 Oct 2015, 8:03pm

andrew_s wrote:
[XAP]Bob wrote:Why go solar when you have a reliable mechanical option available? A dynamo hub will give you lots of glorious power to use.

I have come across someone complaining that dynamo power wasn't adequate when touring in a mountainous area.
They were going too slowly when grinding up the big hill in bottom gear to generate usable power, and they couldn't harvest enough of what was available during the short period whizzing down the other side to make up the shortfall.


That's what I found, I used a dyno hub and a solar panel, the first battery I tried would actually discharge into the panel on dull days, the portapow battery is great and takes a trickle charge and on sunny days I could fully charge the 10000mha battery.
I found it a very viable solution used along side a dyno hub..