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UK Window Cleaning Forum => Window Cleaning Forum => Topic started by: nathankaye on January 12, 2018, 12:24:36 pm

Title: Spruce or P@F a little solar panel help please
Post by: nathankaye on January 12, 2018, 12:24:36 pm

Hiya chaps.
Wondered if i can ask a little help.
Currently i setup my panels in series to try and get the most from these winter days with little sun and Ive tried to stop checking on it for a while. However its been a slow day today and so i checked it out again.

So i have a 50w and a 20w connected. On the positive wires ive connected on/off switches and then both panels are connected to a watt/amp meter so I can see what each panel is producing. Then ive connected positive of one panel to the negative of the 2nd panel. Then respective +   -   connected to my MPPT.
My problem is, my panels are showing a production of over 20v on one and about 11v on the other. So im expecting a yield of over 30v so the MPPT can do its thing.
Now I might not be understanding fully how the MPPT works, but its showing an input of less than 19v and going down to 14v   even though the main panel shows over 19v.

What have i done wrong?
Haha did a little vid with same info, but you can see what ive done
https://youtu.be/KHH3ih_q_jQ

Appreciate your more knowledgeable advice

Title: Re: Spruce or P@F a little solar panel help please
Post by: P @ F on January 12, 2018, 07:14:05 pm

I think i can see what you have done , by putting the + of one meter to the - of the other they  are in some way canceling out or backfeeding the voltage , I have found that running in series is best for overcast days , and running parrallel for sunny days .

So , instead of worrying about what each panel is giving you at any given time , you should be more concerned about what you are getting from panels combined before and after MPPT .

This is how i have set my system up , this way all that needs to be changed is from series to parralell wiring .

The basic setup is ........

 

Title: Re: Spruce or P@F a little solar panel help please
Post by: P @ F on January 12, 2018, 07:30:40 pm

And im sure you know this , but just in case  ;D

Title: Re: Spruce or P@F a little solar panel help please
Post by: nathankaye on January 13, 2018, 12:15:20 am

Cheers P@F
As soon as i read what you put it made sense. Dont know why I didnt realiseit.
The meters read only one way so they must have a blocking diode in. I need to connect them before hand like in your diagram.
Cheers, I'll jig it around tomorrow