I run a charity educating under-privileged children about the environment (www.daktaribushschool.org). We live in the remote bush near Kruger Park in South Africa and have no electricity. Most of the project is run on solar power.
I was donated about 15 solar garden lamps, however the animals have broken them. I have saved the pieces.
They run on a small (60mm x 60mm) solar panel which charges 2 x 1.2v rechargeable batteries. There is a small circuit board and they have 2 LED lights. Each panel seems to give out 4.2v in direct sunlight.
I was also donated about 30 LED bulbs, with 30 resistors, and about 10 x 3.6v batteries.
I thought I could connect all the solar panels from the garden lights, in parallel, then connect them to the batteries (also in parallel) then make a 30 x LED array to provide light.
I know nothing about electricity, so I do not know where to wire in the resistors, how many I will need etc. The resistors are marked RE5CF27R, and have three bands, Red, purple, black then a space and a gold ring. This means nothing to me.
Can anyone help me with the wiring, and maybe explain why I need the resistors?

 

Hello,

Sorry to hear the solar lamps were broken by the animals.
Do you have more details on the leds?
Do you also have more details on the batteries?

The resistors are needed to limit the current for the leds.
Whitout resistors the leds would burn out almost immediatly.

Bertus

 

With some specs on the parts you have, we can whip something up.

This will explain what the colors represent on the resistors:
http://www.logwell.com/tech/components/1resistor_color_code.html

 

The LEDs are white and the packet says only 5mm. The batteries are sets of 3 circular batteries (blue wrapping) and the label says "Cellular phone" batteries. They are marked 3.6v

 

Friend, I think what you are doing is commendable. A Very good thing.

I will try my best to give you the information you need to get things together, in a teachable form for the kids.

I, and others here, can only help you with what you have, if you can give us specs. Which you have done well so far.
Is there a brand name on the solar lights? I may be able to get a schematic of some more part specs online from the name and model numbers.

Are there any other markings on the batteries? Maybe a number with an 'mAH' after is.. Like 3300mah ?

That will tell us the amount of current available to your leds.

 

OK I went to the workshop and checked. I have 17 similar solar panels. I have 15 batteries. They are in a sealed pack, branded "Circuit Centre" and labeled r"rechargeable cordless phone battery" Each pack has a number 3XN280BC No 2P373 3.6V 280MAH

 

I also have about 60 LEDs, just labelled "white 5mm"

 

OK, do you have shop standards? A multi-meter, soldering iron?


Im guessing a yes on the meter, you said you were getting 4.2 in direct sun. How about current? Can you measure the amperage (mA) in direct sun?

Once we have that number, we can calculate the total series or parallel (or a mix of both) for the system we can build.

 

Thanks. We are at GMT +2 (South Africa) and it is dark at the moment. I will try and measure the mA on my meter tomorrow (if the sun is shining - it has been overcast for about three weeks - very unusual!) Yes, I do have a soldering iron, when I run the generator.

 

Ok, good, You wont DEFINITELY need to solder this all, but it would be the way to go.

Is this your battery?

It is a NiCd battery, and we will be using low currents, so we can make a charger without too much hassle.

Do the broken solar lights have a circuit board in them? There may be a charging circuit we can salvage from a few of them. If not, we will figure it out.

Do you have a digital camera to show us your parts? A cell phone camera will do.

We are really going to have to have that 'current' reading from the panel to get moving, but this will get things churning.

The resistors you have, (the red, violet, black) are 470 ohms, Did you have a chance to look at the link I posted in POST #3?

It has the color codes to decode the resistors. You should bookmark that.

 

Hi there. Today the sun is out, but varies. Clouds every now and then. I have tried to take the measurements in similar light, but not really possible. Perhaps these readings will help you anyway.
With a resistor between the + and - on the panel: Meter readings: 200mA 36, 9VmA 2.6, 1.5VmA 16
With a resistor just on the (+) : 200mA 39, 9VmA 12, 1.5VmA 38
With no resistor : 200mA 10.3, 9VmA 0.8, 1.5VmA 3.2
With the panel half covered, and a resistor between (+) and (-) : 200mA 10.3, 9VmA 0.8, 1.5VmA 32 (a bit more cloudy for this one)

Double check of quantities available: 67 x 5mm LEDs (white)
30 x resistors
14 x batteries
17 x PV panels
ideally I would like to make a circular array of all the LEDs to provide quite good light in one area.

 

I thought I posted a reply, but it is not here. Will try again. Three different settings on my meter for mA! The weather does not help. Sun comes out then disappears in clouds. I have tried to do all readings in direct sun, but not really possible.
With a resistor between (+) and (-): 200mA - 36; 9VmA - 2.6; 1.5VmA - 16
With a resistor just on (+) : 200mA - 39; 9VmA - 12; 1.5VmA - 38
With no resistor : 200mA - 38; 9VmA - 0.8; 1.5VmA - 38
With half panel covered, and a resistor between (+) and (-): 200mA - 10.3; 9VmA - 0.8; 1.5VmA - 3.2 (more overcast for this reading)

Update on supplies availabel: 67 x white 5mm LEDs
30 x resistors (red, purple black gold)
15 x 3.6V 280MAH batteries
17 x PV panels
Ideally I would like to mount all the LEDs in one circular array to provide better light in one area only.

 

I have 10 of the old garden light circuits. They have 2 x LEDs and charge 2 x 2.2V rechargeable batteries. I have taken photos of everything and will try to attach here. If it doesn't work, have you an email address?

 

I dont know how to download the pics. It says URL of image. There isn't one. It is on my computer! (You see electricty is not the only thing I dont know about!!!!) I can send them by email to you?

 

my email is : <snip> attn Ian

 

Hello,

You can post images using the Manage Attachment button below the edit field.

Attachments and Images

How do I attach a file to a post?
To attach a file to your post, you need to be using the main 'New Post' or 'New Thread' page and not 'Quick Reply'. To use the main 'New Post' page, click the 'Post Reply' button in the relevant thread.
On this page, below the message box, you will find a button labelled 'Manage Attachments'. Clicking this button will open a new window for uploading attachments. You can upload an attachment either from your computer or from another URL by using the appropriate box on this page. Alternatively you can click the Attachment Icon to open this page.
To upload a file from your computer, click the 'Browse' button and locate the file. To upload a file from another URL, enter the full URL for the file in the second box on this page. Once you have completed one of the boxes, click 'Upload'.
Once the upload is completed the file name will appear below the input boxes in this window. You can then close the window to return to the new post screen.
What files types can I use? How large can attachments be?
In the attachment window you will find a list of the allowed file types and their maximum sizes. Files that are larger than these sizes will be rejected. There may also be an overall quota limit to the number of attachments you can post to the board.
How do I add an image to a post?
If you have uploaded an image as an attachment, you can click the arrow next to the 'Attachment Icon' and select it from the list. This will be inserted into your post and can be located where you want it displayed.
To include an image that is not uploaded as an attachment and is located on another website, you can do so by copying the full URL to the image, (not the page on which the image is located), and either pressing the 'Insert Image' icon or by typing

after it, ensuring that you do not have any spaces before or after the URL of the image. You can insert pictures from your albums (?) in this way too.

Bertus

 

You can also press the 'Go Advanced' button which is next to 'Post Quick Reply' that will take you to the area were you can find the 'Manage Attachments' link below the box you type you message into.

 

Daktari, I might be able help with some info. I am Johannesburg and I have two of these solar garden lights at home. They are quite common and chances are they're from the same manufacturer.

I will try and open one of them tonight, perhaps that will help at least identify the components we're working with here. I will get home in about 4 hours and will see if I can post a photo of pcb board, then you tell me if this is what you've got.

 

First of 10 pics

Taken in high res so you can see the parts etc and markings

 

Hello,

I merged the posts.

You can have upto 6 pictures per post.
Just fill the lines at the "upload from my computer" with the locations of the pictures.
(there are three lines you can fill in at once).
Resize the pictures to about 800X600, this will make the up and download quicker.

Bertus