Kevin Davies Director Centre For Appropriate Technology Malawi 3.9.08

Hi Graham,
 
 
Back to business - our trip went very well and we developed a simple range of products that are being sold. Suffice to say demand outstripping supply! I have asked the chaps for a list of items needed to keep production up, so will be contacting you again shortly.....we start little by little, but it's viable and I find a good test is if our staff queue up willing to purchase the product.
 
Attached is a couple of photos for your interest.
 
I need to get my maths correct for the phone charging. Most chargers seem to be 3.6v and 350mAmps. How many 0.35w panels needed in parallel? Or 1.8w panels? Do you have diagrams to follow?
 
All the best and speak to you soon.
 
Kevin
 
Director
Centre For Appropriate Technology Malawi

Thanks a lot for the photos - not many people send me useful info!
 
But I have some queries.
 
1. Why do you make elaborate frames adding to the cost of panels?

The frames house the panel, battery and wiring. The socket is external and ready to power leds and/ or radio.
 
2. What is inside the small white plastic containers? I first assumed LEDs but where are the batteries?

The plastic film canisters (locally available) house the terminal strip and led of choice. These connect to the above with the plug. We used one during our trip for camping etc and it was really quite excellent for cooking, playing cards and as a night light for the kids in the tent.
 
3. Any feedback on the oil lamp conversion? Does the glass globe not cut down the LED light?

This is more expensive but our research shows very desirable. We only made two and these are being trialed. We followed your diagrams, including the slide switch for the light, and there is a socket to connect the panel and a socket to power radio. With one battery and 0.35w panel (supplied by you) we charged for around 6 hours and this then provided light and powered a small radio for over 12 hours. Staff very impressed. We added reflective film (inside of cigarette packet) to the column and this offered plenty of reflection, therefore loss of light through glass not such an issue.
 
Regarding mobile charging, you have not got the 'picture'.
OK, help!

The chargers you are referring to are for charging into the phone which we do not recommend - see report below from Tanzania.

is it not a neater way of charging? Taking batteries in and out regularly may damage phone? I have seen 'universal' solar phone chargers in the inflight magazines, expensive...

We suggest removing the battery and provide a tiny module plus info on simple connector - see pdf.
thankyou for this. Is this a simple version of the 'kobe' John refers to?

More info if you want to have batch production. yes please
Also consider getting $2 Chinese batteries so people can be solar charging a battery while using the phone!

Graham