Non MPPT Controler Question

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Joined: Tue Jan 15, 2013 3:10 pm

Non MPPT Controler Question

Post by Solar98632 » Tue Feb 09, 2016 12:17 am

As you all know I have a harbor freight Charge Controller and a Harbor freight 2,000 watt Inverter.
When it comes to the sun a weird thing occurs perhaps it is the ARMs I a m using, they do have a faster charge rate.

Ok. So I am at 12 amps happily charging away on my solar power.
An low and behold i noticed I have an error in math.

When checking the panels out put going in to the charger I noticed it seems to flex between 13 an 19 volts. On full sun.

Which leaves me a tad perplexedon the math.
Here is where it gets weird.

First lets get the known wattage. .
My wattage for home electronic is 50 Watts
My home Fridge 183 Watts..
This is a total of 233 Watts.

So that math is confirmed and is solid

Now here is the weird thing.
If my through put from the panels is 13 vdc and the thing is reading 12 amps well there is an issue.
Of only 156 Watts. Which means..not sustainable.

But then I noticed my voltatag was going up. I went to 13.1 then 13.2 and so on.

Well here comes the fluctuations.
Remember when i I said I get variations in the in put?

Ranging from 15 to as high as 19 ?

Lets try something shall we?

Now lets try 19 x12 = 228 Watts. Still not sustainable.
So after scratching my head . and gnashing my teeth.

There is only one way to figure my true voltage in

233 ÷12 = 19.42 (rounded)
Which gives me a break even .

So lets say I now can take
20x12 that gives me 240 Watts.
Now that brings me up to sustainability plus charging the batteries.

So, on a cold clear day, I can max out at 20 vdc in.
And take in at 12.5 amps peak.

How ever, if I want to go by what I have
45x5=225 Watts.
Which would be 18.75 vdc in.
225÷12 =18.75

So, there you have it.
My very weird shouldn't. But does system.

I plan to build a new frame for the panels. To get them better organized and off the ground.

I am still scratching my head.
If you seen the video I uploaded, you'd see what I mean.

Posts: 246
Joined: Tue Jan 15, 2013 3:10 pm

Re: Non MPPT Controler Question

Post by Solar98632 » Fri Feb 19, 2016 12:27 am

Any ideas?

Posts: 246
Joined: Tue Jan 15, 2013 3:10 pm

Re: Non MPPT Controler Question

Post by Solar98632 » Mon Feb 22, 2016 9:02 pm

Ok i have some data.
After purchasing a new Voltmeter, the Harbor Freight panels are producing. Voltages between 13 (cloudy day) to 20vdc (full sun)

My max amps have been 15.2 amps.

This video demonstrates
What is is i am trying to speak of.

[url[/url] just in case the above url does not function.

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Re: Non MPPT Controler Question

Post by techman » Sun Dec 11, 2016 10:17 am

Any updates on this?

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