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The Initial Concept

A project log for Solar Power Bank

Power bank charged via solar uses old batteries

csavageC.Savage 03/29/2017 at 00:520 Comments

It started with an Idea or rather..a problem. We live in a technologically advanced society where we carry small devices with us all the time. They need energy to do so. Being in a remote location poses a problem. Sure it has a battery, but that battery will run out in due time. I could lug a generator to the site..but then I need gas and it also will pollute the area with noise. Solar is the obvious option.

I had done a previous project where I wanted to charge my phone via Solar. Well it worked, until the boost IC blew for unknown reasons. Luckily someone's truck was nearby and I could charge my phone overnight using an adapter.

So I started from there. I wanted to also do a total rebuild of my solar panel, as it really didnt give enough power. It is made of 10 semi broken 3x6 cells. Gives about 4.5V at 2A. Not really enough for charging your phone without a boost converter. Something also happened to the panel during the last few tests as now it seems to give only 500mA. I suspect there is a break in one of the cells.

The new panel will consist of 12 3x6 solar cells. I tested an individual cell and it gives about 435mV @ 2A. Open Circuit Voltage is around 575mV. This was around Noon in the winter sun. The whole panel should give 7V Open circuit and 5.22V under full load.

Construction Will be of Wood and Plexi or Acrylic. It will be somewhat water tight, but not fully (so NEMA 3/4/12). It really wont sit outside all the time either. I do plan on sealing it with caulk.

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