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Folding Solar Charger


#1

Noticed in my local Maplin store this morning that they have their folding ‘briefcase’ style solar panel chargers for 12v on special at the moment. 1/2 price at £9.95. I think the weight was around 650 grms. Not a bad price for them and handy to keep in the car if nothing else.

73
Jonathan
M6HBS


#2

In reply to M6HBS:
Hi, Jonathan.

I don’t want to appear negative, but I think you might be a bit disappointed with the performance unless you only want it for trickle charging a car battery. It’s rated at 2W but you may never achieve it. The one I showed on Thursday is rated at 6W but the maximum I’ve ever got out of it is 4W in full sun. Anything less that full sun - forget it. Maybe if I was nearer the equator …

It’s also a bit on the heavy side for summit use. My Power Pocket is 250g including all the cables and regulators etc and I can justify carrying that on multi-day trips as it saves me taking an extra battery of equivalent weight.

If you get one, please prove me wrong.

73, Richard


#3

In reply to G4ERP:
Hi Richard

Must admit, I didn’t look at the Wattage when I saw them this morning. As you say, 2 Watts is a tad too low for anything much apart from trickle charging.

I only have 2 handhelds for portable use at present, so I don’t really need one.

I was trying to remember the company you obtained yours from. Was it Green Orb or something like that??

73
Jonathan
M6HBS


#4

In replt to M6HBS:

Hi Jonathan,

I bought one of the small 1.5 Watt solar panels from Maplin designed to be left on a car dashboard to trickle charge the car battery, which is sufficient to charge a 7Ah Slab in reasonable daylight & of course much better in good sunshine.

It takes several hours to bring a partially discharged SLAB back to full charge, but using a small radio such as an FT817, I could see it being useful if I was away on an extended trip away from a mains / vehicle charging option, & it may keep a SLAB from discharging too much if used while operating.

Although Solar panels have come a very long way in the past few years, they aren’t yet at the stage where you could power a 100 Watt HF radio from a panel the size of a QSL card. HI!

I wouldn’t carry the suitcase sized item described earlier up a summit myself, but it may be interesting to see how much more time, if any, a small solar panel would give when using it to trickle charge a SLAB while in use. Certainly the current drain on TX would drain the battery as usual, but a few watts from a large enough solar panel should compensate for any current drain on receive.

How many Amps does the radio draw on receive? How many Watts does the panel produce @ 13.8V? A simple bit of Ohms law should let you know if it is worthwhile.

Good luck in any case :slight_smile:

73,

Mark G0VOF


#5

In reply to G0VOF:
Hi Mark

I guess at the price, they could be worth a try as a back up to trickle charge a slab or similar. Size wise they are about the size of a 10.2" Notebook PC, but are shaped like a briefcase.

73
Jonathan
M6HBS


#6

In reply to M6HBS:

Select Solar Ltd is one of the companies in UK to sell different sizes of solar panels. The solar power is expensive for the investment, but then you can produce your own power for free. My APRS weather station is now powered by a 7 W solar panel, see http://aprs.fi/f5vgl-8 . It is still under test and no wind/rain readings for the moment. For the ATS3B I made a circuit, which adds a load resistor in parallel to the output of the panel if the voltage exceeds 12 V. A simple comparator and transistor circuit.

73, Jaakko OH7BF/F5VGL


#7

In reply to M6HBS:

I think that was the company but I can’t find them on the web now - mind you, they took some finding first time round. It’s the only panel I’ve found that’s worth considering for Summit use.

Here’s the panel:
http://www.rewarestore.com/pockets.html
and here’s a photo of it in use:
http://www.flickr.com/photos/91098242@N00/4523503117/

You’ll have to wait a while for it to come out, but I’ve included quite a lot of info and results in the next edition of the Great Outdoors chapter in the RSGB Handbook. If you’re really interested in solar power, e-mail me.

73, Richard


#8

I have the “4W” version of the maplin one which was on special offer last summer. I did some measurements on it which I might get round to publishing now. The maximum power, from memory, was about 2W. It is very unlikely to be worth using one unless you are out for a long exped in the summer. Mine has been useless all winter (it can’t even light its LED when on the windowsill).


#9

In reply to MM0HAI:

I have had the same problem with a 4w one from Maplins ( mainly useless and mine was a present for xmas from the daughter!!))

Tony


#10

In reply to 2E0LAE:
Hmmmm… Sounds like this one is best left well alone then!

Richard… Thanks for the info on the Power Pocket. I don’t need one yet, but I’d like to get some portable gear at some point (817 or similar) so it’s worth bearing in mind for the future.

73
Jonathan
M6HBS


#11

The Power Pocket device seems to be out in other names also. I bought the Sunlinq which seems to be exactly the same (6.5 W @ 12V, 250 gr). The price is USD 90 + shipping. Recommended dealer: SolarCapitalist

http://cgi.ebay.com/Global-SL-6-5-W-Folding-Solar-Panel-w-12-V-Power-Cable-/160470422793?pt=LH_DefaultDomain_0&hash=item255cc85509

Haven’t done any benchmarking though, it just works fine for me!

Anders SM0HPL


#12

The Power Pocket device seems to be out in other names also. I bought the Sunlinq which seems to be exactly the same (6.5 W @ 12V, 250 gr). The price is USD 90 + shipping. Recommended dealer: SolarCapitalist

http://cgi.ebay.com/Global-SL-6-5-W-Folding-Solar-Panel-w-12-V-Power-Cable-/160470422793?pt=LH_DefaultDomain_0&hash=item255cc85509

Haven’t done any benchmarking though, it just works fine for me!

Anders SM0HPL


#13

In reply to SM0HPL:
This an area of interest for me also, I am looking ways of running a QRO ssb station for an extended period beyond the life a 7ah SLAB offers.
I am looking forward to the experiments which hopefully will start soon.

Sean M0GIA


#14

In reply to M0GIA:

Sean

I don’t think that a 6.5 Watt solar panel is quite enough for your requirement!

73

Richard
G3CWI


#15

In reply to G3CWI:
You are right Richard, I have a 15w solar panel which will not be enough either. If 5w cw and 10w ssb is considered QRP then QRO is any amount of power above these levels?

I am thinking of using around 50w+ from a summit, I know plenty of activators do use these power levels but for me it will be something new to try from a summit.

Sean M0GIA


#16

Hi,

I have two BN PowerFilm R15-1200 surplus for £150/pcs. Rated for 1.2A on 15.4V. I measured the rated amps in full sunlight during winter, so I think in summertime it shouldn’t have any problem either. When fully overcast they give you 100mA in closed circuit.

Hope this post does not violate any rules, if does please remove.

Thanks,
Peter


#17

The weight of the LiPo batteries we’re using these days is so low that just about the only time it’s worth taking the panel with me is on multi-day backpacking trips. Any other time, I’m better off taking an extra battery pack instead.

Using the 6.5W panel we’ve mentioned, the maximum current you can get is about 350mA (at about 11V) - or the current taken by an FT-817 on receive. If I’m doing a summit a day, I can just about keep the 3S LiPo battery charged if - and only if - the weather is good.

If you want to charge a 4S pack or any other type of pack that would drive a 50W rig, you’ve got no chance unless you take an inverting charger with you. The standard RC chargers won’t work with the panel output so you’ll have to build your own to cope with the wide input voltage range.

I tried using mine to recharge my 3S packs at home, but I lost patience with rotating the panel to point at the sun. Sorry if this all sounds a bit negative, but they’re reasonably expensive devices which do have a use but that use is quite specialist.

73, Richard


#18

In reply to G4ERP:

Those panels are a bit overkill for my PP3 - and at well over 100 QSOs per battery I can carry a few spares!

73

Richard
G3CWI


#19

In reply to G3CWI:

Quite a few spares … :slight_smile:


#20

In reply to M0GIA:

"This an area of interest for me also, I am looking ways of running a QRO ssb station for an extended period beyond the life a 7ah SLAB offers. "

Ever thought of 2 x 7AH slabs?