Help a new user understand... Low panel output / crappy converter?

Started by electron, Mar 28, 2024, 11:54 PM

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electron

Wanted to get started with solar for a cabin. I bought a 50 watt Renogy panel and the classic cheap solar charge controller with an MPPT unit on my wishlist further down the road.

I have my panel outside in direct sunlight, not a cloudy day.


Here's the setup: You see two batteries but I'm only connected to one. I am concerned about several things. The "load" light on the controller, should that be on? I'm only getting 5 watts & .38 amps? I didn't expect 50, but I didn't expect 5 either...


Different configuration just for my own knowledge. I've got the meter inline with the battery charge.


Any thoughts are appreciated.

Thanks!

I am concerned about several things. The "load" light on the controller, should that be on? I'm only getting 5 watts & .38 amps? I didn't expect 50, but I didn't expect 5 either...

My load light is on when it's charging, I think it only goes off if the battery is low, in your case on a 12V system probably 10.5V maybe?

Here's some video, I use the same kind CMP 12/24 but put a small extra heat sink so it can handle a little more amps. You can see 14A in the second video, I have had seen them handle 20A.
[media]http://www.youtube.com/watch?v=8nJfNdfKSvg[/media]
http://www.youtube.com/watch?v=8nJfNdfKSvg

[media]http://www.youtube.com/watch?v=fbVrzfIObJU[/media]
http://www.youtube.com/watch?v=fbVrzfIObJU

It looks like the panel is getting some shade in that picture, is it behind a fence? Any shading will cut back the power, even a small corner shaded. It also needs to be pointed at the sun angle as best as you can get it, generally face it south and adjust it at least twice a year for tilt.

On that CC, generally it starts backing off at 14.25V (12V system) but if you watch the second video you can see how the panel's amps go down as the volts go up, that's just the way it is.

When you see the "charge" LED start blinking on your CMP 12/24 that is the controller backing off, meaning your batteries are charged or getting there.

The controller I am testing on the second video seems to have a lower on/off point so I prefer the others. The blinking you see is slower than the CMP 12/24 you will see, it's pretty fast.

And you can see the added heat sink better on the second video. It can't be too heavy of a heat sink, it's only held up by the mosfet leads, this is a small old 386 PC heat sink from very old computers.

See this thread for info on how I beefed it up:
http://techluck.com/cgi-bin/YaBB.pl?num=1313110955
Thanks for your reply! I saw that article before I bought my kit. I have also heard that these chargers are not PWM, they're just voltage regulators... I'm looking at getting a better controller, so might not bother modding this one.

I had some time to move the panel around and get full sunlight around 6pm today. I started getting about 25 watts and 1.5 amps from the panel. I noticed if I cover just the corner of the panel with my fingers the voltage output drops to 4 or 5 watts. I REALLY didn't expect that. I've got my homework to understand how that works!