Advice please - stupid question again?

[dangerman]

Ok so I'm off on my holidays and I'm occupying myself with a simple budget project (as mentioned in another thread).

So far I'm pretty much progress free. Just discussing ideas. But I'm a little bit stumped.

I would like to put a small solar panel in my garden, maybe on my shed, that will live there permanently and yet could be brought down quickly and easily for holidays or whatever. I want it to simply charge batteries which can in turn power lots of other things. My intention is to have the smallest possible solar panel and not waste any of it's energy. Initially, I was thinking 3w - it would charge, I reckon, a 20000mah power bank in a week or so. But then, what if I wanted to charge my phone a little more often than that? And so I thought I would aim for something slightly bigger and just use up the extra power to keep my iPad and tablets etc topped up too.

The problem I'm having is that I can't find any ready made solar panels with a USB output which are fully waterproof. They all seem to similar to the ones I already have - here is a nice little 3w for £8.48 and some bigger ones with it. http://www.ebay.co.uk/itm/201097835609

I emailed them and they said no to rain or water whatsoever. So I think I may need to make my own. But I don't know how.

I reckon I'll need one of these USB outputs - http://www.ebay.co.uk/itm/DC-DC-Buck-se ... 43d8ec8f58, a diode and also a solar panel similar to this - http://www.ebay.co.uk/itm/261826646110? ... EBIDX%3AIT Plus some cable so that the panel can sit out somewhere and the wire can travel into my nice dry shed (or tent if I take it away).

I want to avoid a 12v panel feeding into a 12v lead acid battery - the system is too inefficient and heavy. I'm after a method of charging batteries directly from the panel in the most simple, efficient and portable way possible. I also want to keep it cheap and cheerful. Maybe it's not worth doing if it's going to cost an arm and a leg.

Any help would be appreciated. I'm aware my maths could be way off, maybe a bigger panel is needed.

I really have no idea what I'm doing.

[poppypiesdad]

http://www.portablepowersupplies.co.uk/ ... b-charger/


Like that ?

[Yorkshire Andy]

I've bought 3 different solar usb chargers and they are pants

Most effective method would be a decent panel with charge controller a small SLA battery think what goes in a fire alarm as a buffer to adsorb any voltage spikes or troughs


Eg

http://www.hardwarexpress.co.uk/np7-12- ... oCgYTw_wcB


And this


http://www.amazon.co.uk/Photonic-Univer ... B009FP2R2K


This contains a charge control unit which you attach your panel battery and load to and it sorts all the charge and supply issues out

http://www.photonicuniverse.com/en/cata ... o-60W.html

On the supply side fit a 12v CIG lighter socket then you can plug which ever car type charger in you want

The benefit of a battery is that you can charge your device whilst you sleep / have power at night and on a gray day have a bit of power in reserve many modern smart phones can draw up to 2a at 5v. My 12v to USB adaptor takes about 0.6a out the battery whilst charging my phone at 1a

[dangerman]

The primary power bank is going to be this 74WH, 20000mah. http://www.amazon.co.uk/gp/product/B00N ... ge_o00_s00

It apparently has no memory or anything, so I should be able to charge it over a long period without worrying about damaging it. I can leave it in the shed and charge my stuff from it each day, or if I decided to take it out with me I could leave my other smaller power banks plugged in, or my iPad to prevent from wasting any leccy.

Good idea?

[dangerman]

http://www.portablepowersupplies.co.uk/ ... b-charger/


Like that ?

Yeah, that's what I already have. I wouldn't want to leave it out on a permanent basis.

[dangerman]

I've bought 3 different solar usb chargers and they are pants

Most effective method would be a decent panel with charge controller a small SLA battery think what goes in a fire alarm as a buffer to adsorb any voltage spikes or troughs


Eg

http://www.hardwarexpress.co.uk/np7-12- ... oCgYTw_wcB


And this


http://www.amazon.co.uk/Photonic-Univer ... B009FP2R2K


This contains a charge control unit which you attach your panel battery and load to and it sorts all the charge and supply issues out

http://www.photonicuniverse.com/en/cata ... o-60W.html

On the supply side fit a 12v CIG lighter socket then you can plug which ever car type charger in you want

The benefit of a battery is that you can charge your device whilst you sleep / have power at night and on a gray day have a bit of power in reserve many modern smart phones can draw up to 2a at 5v. My 12v to USB adaptor takes about 0.6a out the battery whilst charging my phone at 1a

Yeah, that's a similar system to what I already have. But I'm after a direct charge from solar panel to my kit. Use the actual power bank and/or iPad as the battery.

[Hamradioop]

You are unlikely to produce a charging current from a solar panel in the rain. So all you need to do is fold it up and put it away when it rains.

[Brambles]

Funny actually, I'm messing around with a 7W 5v panel and a battery to run a water pump in a little aquaponics system I have in mind, so I see what you want. This one states it's waterproof. Maybe contact the seller for advice.

http://www.amazon.co.uk/Vakind-Waterpro ... B00O7GO8D8

I already have a folding panel just like the one you have linked to, so I'm going to try keeping it in a waterproof pouch outside and see if it works. If not...well, I'll think of something else. We'll have to update this thread as we go along.

[dangerman]

You are unlikely to produce a charging current from a solar panel in the rain. So all you need to do is fold it up and put it away when it rains.

I know, it's all but useless in the rain. The thing is about England though, one of the many annoying things about this place, is that it's often just showers. Sunny and clear most of the day, then a mini deluge and then sunny again. It happens all the time. And so it's impractical to come home every time it looks like there is a shower on the way. Even on sunny days when the weather girl on GMTV has promised no rain - it still rains.

So really, if I want to make the most of all of the sunlight, it needs to be waterproof. And fixed firmly too, so that it's generally weather proof.

Funny actually, I'm messing around with a 7W 5v panel and a battery to run a water pump in a little aquaponics system I have in mind, so I see what you want. This one states it's waterproof. Maybe contact the seller for advice.

http://www.amazon.co.uk/Vakind-Waterpro ... B00O7GO8D8

I already have a folding panel just like the one you have linked to, so I'm going to try keeping it in a waterproof pouch outside and see if it works. If not...well, I'll think of something else. We'll have to update this thread as we go along.

I think that advert is a bit ambiguous though. The eBay one says the same - waterproof materials. I think that just means the fabric itself and the fabric. It doesn't state that the whole thing is waterproof as such. I think it's the USB output that's not good in the rain, and the general wiring. Hence why I would like to add a long wire to fix the panel a fair distance from the plug. I might email them and ask about warranty in case of water damage - maybe I can have them promise a replacement or refund if it fails.

[Brambles]

I also came across this....

http://www.amazon.co.uk/Levin-trade-Eff ... olar+panel

And this.

http://www.tmart.com/5W-1A-USB-Port-Out ... tAodKW8AQg