Using full power from solar panel usb charger

Thread Starter

nickbuhling

Joined Oct 27, 2017
28
Hello everyone. I made a solar usb charger that, by having three 6W panels + 5V dc-dc converters in parallel, must be capable of providing 2 to 3 amps in full sun. I have connected a female usb connecter to the panel outputs and shorted the data pins as I read somewhere else that that tells a device it is a dedicated charger and can provide up to 1.5A.

Now when I connect a powerbank or phone to it via a usb current and voltage meter, it says to only charge the device with 500 to 800 mA. I know the panels have more power to provide because when one panel is blocked by hand, the current is maintained on the usb port.

I read having 2V on the data pins might help, but I also read that that might only help with charging apple phones. Furthermore adding an additional usb port and charging 2 devices at the same time might double the power generation but it is not ideal ofcourse.

So my question is, what do you people suggest to do in order to utilize the maximum amount of power from the solar charger? Thanks!!
 

Thread Starter

nickbuhling

Joined Oct 27, 2017
28
A module like this one (though I am not partucularly recommending this one) is your best bet. It deals with charge current negotiation with the device, and has other features.

https://www.amazon.com/Charge-Voltage-Controller-Regulator-Sep-07/dp/B07PMLRQKQ/
Thanks for your kind help. My panels had these on them (see image). I just combined their power lines and ignored their data lines. They look kind of similar. Do you think I could use them somehow or should I find something you suggested?
 

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Yaakov

Joined Jan 27, 2019
1,535
Thanks for your kind help. My panels had these on them (see image). I just combined their power lines and ignored their data lines. They look kind of similar. Do you think I could use them somehow or should I find something you suggested?
I think you should leave out the existing converters and use a charge controller like the one I linked which should handle the parallel input of the three panels fine. You need something that can provide the proper signaling to indicate capacity.
 

Thread Starter

nickbuhling

Joined Oct 27, 2017
28
I think you should leave out the existing converters and use a charge controller like the one I linked which should handle the parallel input of the three panels fine. You need something that can provide the proper signaling to indicate capacity.
That sounds like a good idea to at least give a try. Hopefully I can find one in the Netherlands. Thanks for your time!
 

Thread Starter

nickbuhling

Joined Oct 27, 2017
28
Let us know how it goes. Good luck.
I found the same board on banggood and found an image (see attachment) suggesting to short the data pins for phones. That is what I already have done currently with the existing boards (which look very similar).
I did not manage to find more boards that have current detection features to manipulate data pins.

I found that not adding the usb voltage and current meter caused to charge a samsung galaxy s6 a little faster. I think up to 1A. Ideally I would ofcourse want it to do fast charging. I think the power is there in full sun but is it even possible to achieve it practically? Like the Qualcomm qc.
 
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