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Best, cheapest way to utilize a 10 volt, 6 amp solar panel? Answered

Hey Instructables friends!

So I have 20 solar cells that are .5 volts each and 6 amps. I plan to connect them in series to give me a 10 volt, 6 amp panel. I want to use the panel in my car to maintain the car battery and power my usb devices and be a general backup power source. The problem is that I am still new to electronics and I can't think of a cost effective, safe, and reliable way to utilize this panel. I need at least 14 volts out of the panel if I am to connect it to the car battery and even then I'm not sure how to limit the charge (I only want 1 amp maintaining the battery) and use the remaining output for other things.

Any ideas are greatly appreciated! I also want to think of a free way to do this if possible.

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I found my solution (already finished the panel) and might make an instructable on it. The cells came already coated with the epoxy coating and I found that cutting them in half with a miter saw worked, as brutal and cruel as that sounds. I was able to end up with 40 (working) solar panels at .52 volts, 3 amps each. I used 28 of them to make a 14.5v solar panel. I haven't had full sun yet to test it in so I don't know how many amps it actually delivers at this point. It should deliver between 2 and 3 amps on average.

So I measured about .52 volts in average sun. I guess my question at this point is this: how can I limit the amps output so that I don't fry a voltage boost module if I buy one? Ebay has lots for just a few dollars but they all have a limit on the input amps and my cells output 6 amps which I feel like would fry anything.

Have you measured their output in full sun? If they go up to 0.7V per cell you're in luck, otherwise there's no free way to do the car batt charging with the PV you have. You would need a dc-dc converter with a 10V input and a 14V output, probably wont be cheap either.

To prevent the batt discharging into the panel at night or during periods of shade, you would need a blocking diode (6amp capable) on the pos wire.

Best scenario is to use 10 cells for usb powering alone and source something else for the car batt

I have lots of blocking diodes so I will definitely use one of those. I will wait for the sun to come up and then measure the voltage! EBay has lots of boost converters from Chinese sellers for a few dollars but that's the part I'm not sure about because they are usually rated for less than 6 amps input. I can also get them from US sellers for a little more but they are the same :P

Even if you have 30 cells in series => 15VDC, that will discharge the battery when a cloud passes by or when not pointed to the sun and definitely at night...

Because it acts like a resistor when darker then bright summer sun !

Won't work on the car battery at only 10V. But you can use it for charging USB devices. So long as it can output about 400mA when loaded.