Building a 36watt panel to charge my devices with . What else can I do with it?

[temp4]

Hi, complete newbie here. I'm building a 36-watt solar panel with usb connectors to charge my mobile devices. 36 watts is kind of a lot for a USB charger I reckon. The ones sold at stores are at most 16 watts it seems. So tell me, what else can my solar panels power? Obviously I would need more than just a USB port of i want to charge or power other things.

Also, with a 36 watt panel, how many devices will I be able to charge simultaneously?

Thanks

[PNjunction]

You didn't specify at what voltage your panel is, 5v or 12v?

Thing is, either way you don't want to plug the panel directly into the cellphone etc.

The easiest thing to do is build a 36w / 12v panel. That means the OCV or open circuit voltage directly across the panel terminals with nothing else attached should be somewhere in the 18-22v range. A "nominal" 12v panel actually has this higher voltage open circuit, not 12v. Let's do the math:

36w / 18v = 2A. (Basic power formula of P/I*E. But that is best-case, you'll likely end up with a bit less. Let's count on about 1.5A max under real world conditions. That would power up most stuff nicely these days.

If you do that, you can simply use a quality mobile DC > USB adapter. My fav for quality is Anker. One problem in the early days was that of trying to find / build a specialized cable to ensure the fastest charging for your device. The "IQ" feature of the modern Anker line has this, and eliminates much of the headache of specialized cabling. There are a few models to choose from. Since they accept up to about 24v, they will work fine and regulate the nominal 12v panel you are making.

If you envision charging up multiple devices in a reasonable amount of time (using a multiple output adapter) during the day, you'll likely want to build an even bigger panel, say 60 watts or so.

[russ]

Hi temp4 - Welcome to Solar Panel Talk!

PNjunction is the guy that can help you very much!

Russ

[temp4]

You didn't specify at what voltage your panel is, 5v or 12v?

Thing is, either way you don't want to plug the panel directly into the cellphone etc.

The easiest thing to do is build a 36w / 12v panel. That means the OCV or open circuit voltage directly across the panel terminals with nothing else attached should be somewhere in the 18-22v range. A "nominal" 12v panel actually has this higher voltage open circuit, not 12v. Let's do the math:

36w / 18v = 2A. (Basic power formula of P/I*E. But that is best-case, you'll likely end up with a bit less. Let's count on about 1.5A max under real world conditions. That would power up most stuff nicely these days.

If you do that, you can simply use a quality mobile DC > USB adapter. My fav for quality is Anker. One problem in the early days was that of trying to find / build a specialized cable to ensure the fastest charging for your device. The "IQ" feature of the modern Anker line has this, and eliminates much of the headache of specialized cabling. There are a few models to choose from. Since they accept up to about 24v, they will work fine and regulate the nominal 12v panel you are making.

If you envision charging up multiple devices in a reasonable amount of time (using a multiple output adapter) during the day, you'll likely want to build an even bigger panel, say 60 watts or so.

Hi, this is the panel i bought.

http://www.ebay.com/itm/351182646996?_trksid=p2060778.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

It says 0.46 volts. Not sure what that means. I was gonna get a 5v diode for it and solder a usb cable to it. It won't be acting as a battery.

Confused,
Temp4

[inetdog]

Hi, this is the panel i bought.

http://www.ebay.com/itm/351182646996?_trksid=p2060778.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

It says 0.46 volts. Not sure what that means. I was gonna get a 5v diode for it and solder a usb cable to it. It won't be acting as a battery.

Confused,
Temp4

The original listing is gone, so it is hard to tell, but I suspect that what it refers to is that the "kit" consists of a bunch of .5V cells which can be put together to make a panel with the output specified.
Not really what I would start out with!

[PNjunction]

I understand your desire to build, and that you've probably read all the recommendations against it from a price/performance standpoint, which is offset by the knowledge learned doing DIY.

How about this - do you have a reference for how a decent panel / regulator should work so you can compare it against your DIY projects?

If not, how about this:

http://www.ianker.com/support-c7-g263.html

While I normally recommend Powerfilm, these Ankers are a bit beyond toy-status. I have a few stashed at home, in the car, and at work for emergency phone charging purposes - mainly because of their generally good quality, and not needing to find a specialized cable for them with the IQ feature.

This would help keep your interest up, and give you a goal to shoot for with your own DIY.

[temp4]

The original listing is gone, so it is hard to tell, but I suspect that what it refers to is that the "kit" consists of a bunch of .5V cells which can be put together to make a panel with the output specified.
Not really what I would start out with!

if you scroll down you can see the specifics

http://www.ebay.com/itm/18W-Watt-3x6-10pcs-Solar-Cells-15-efficiency-for-DIY-solar-panel-battery-charge-/351182646996?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2047675.l2557&nma=true&si=U9gz3tnfNvS%252BozKxM9NDoFPeYdE%253D&orig_cvip=true&rt=nc

[temp4]

I understand your desire to build, and that you've probably read all the recommendations against it from a price/performance standpoint, which is offset by the knowledge learned doing DIY.

How about this - do you have a reference for how a decent panel / regulator should work so you can compare it against your DIY projects?

If not, how about this:

http://www.ianker.com/support-c7-g263.html

While I normally recommend Powerfilm, these Ankers are a bit beyond toy-status. I have a few stashed at home, in the car, and at work for emergency phone charging purposes - mainly because of their generally good quality, and not needing to find a specialized cable for them with the IQ feature.

This would help keep your interest up, and give you a goal to shoot for with your own DIY.

yeah basically what I want to do is make one of those portable solar chargers for natural disaster season and for outdoor use. so I bought a bunch of cheap solar panels and now I need to learn how to wire them up so that I can charge my devices with it.

[russ]

yeah basically what I want to do is make one of those portable solar chargers for natural disaster season and for outdoor use. so I bought a bunch of cheap solar panels and now I need to learn how to wire them up so that I can charge my devices with it.

Yep, bought a bunch of cells - now you have spent a few bucks and have nothing.

[SunEagle]

yeah basically what I want to do is make one of those portable solar chargers for natural disaster season and for outdoor use. so I bought a bunch of cheap solar panels and now I need to learn how to wire them up so that I can charge my devices with it.

Unfortunately those cells are very brittle and would require mounting in a rigid frame. That may be considered "portable" but not my definition.

Sounds like you are looking for one of those solar panels that are light weight and fold up for easy transport and "when stationary" can provide some level of charging for a cell phone or ipad. I do not believe you can purchase the parts for that type of solar panel to build one yourself.

[nomadh]

I did a small system like this for camping. I guess you could build your own panel as a fun diy but at $1/watt I didnt see it. I got a rigid 80 watt panel. It peaks around 20 volts so I got the little charge controller from amazon and I bought a used golf cart battery. Even in the mostly shade of yosemite it kept phones, gameboys and dvd players for 20 people running all week. With all the toys and screens we didn't have to look up an enjoy nature for even 1 minute there.
Doing it again I might opt to get the flexible panel but overall it worked great for about $150 total. Now its just sitting at home so I bought a dc pump so I can run it during the day for my koi pond and put my ac pump on a timer to come on at night.

[Jskeyes2]

So long as you can use your phones!