new panels with new charge controller will not charge.

[DixieMtCR]

I need help trouble shooting my new “not working” solar panel kit!

I purchased a 500w system which includes 5-100 Watt Mono Panels with z mounting clips, cables to parallel all 5 panels, a 40A Midas Y Series Charge Controller (MY40), and cables to connect the charge controller to the batteries. These items were a kit from Amazon purchased 2 weeks ago. With all the snow we were having it was impossible to build a rack and install the system outside upon arrival. It is to be stationary for off-grid emergency medical power and lights.

I also purchased 4 deep cycle lead acid batteries which are 100Ah each for a total of 400Ah.

I also purchased a Renogy 3000 Watt Pure Sine Wave Inverter. Bigger in case I want/need to expand the system with more panels and batteries.

I connected up a small test system in the house. I only tested one panel and the charge controller in this test. I used a smaller working battery bank of 2 12v batteries in parallel that have a 1000w pure sine wave generator. The test was to set up to use 1 100w panel and the charge controller to see what charge rate I could get. The panel was positioned vertical in a south facing window. The open circuit voltage of the panel was 18.3 volts. I tested another panel and it was almost exactly the same. The panels says 17.9 volts printed on the back.

Test system did not charge. The charge controller always displayed the panel voltage at 0.1volts less than the battery voltage, except at night when the panel voltage dropped to 0 volts. I ran inverter current all night and it brought the battery voltage to 11.5 volts as measured by the controller and a portable voltmeter. The controller flashes its screen saying battery was low. Oh Really, then charge it!

Anyone have any ideas? Nothing smells, nothing is hot or making any noise. The display on the controller seems to be working but it would surely appear that the controller is not functioning. All wiring has been double check. All 4 wires! Two from the panels, correct polarity. Two to the batteries, correct polarity. Nada! Two different panels were tried to eliminate the possibility of a bad panel.

 

[snoobler]

Welcome to the forum. Open the window and confirm there is absolutely no shading on any part of the panel.

 

[DixieMtCR]

Welcome to the forum. Open the window and confirm there is absolutely no shading on any part of the panel.

Are you saying that shaddows will shut the system down for the entire day? I live in the woods with the chance of a shaddow sweeping across the array during the day. That will kill the system or just cut efficiency during shaded times? I'm confused.

 

[snoobler]

Depending on the panel, even partial shading can have a huge impact on panel production.

 

[HRTKD]

Since you have the panels in parallel, shading of one panel should not affect the other four.

Some charge controllers need the source voltage to be as many as 5 volts higher than the battery voltage to initiate charging. Try connecting two panels in series and see what you get.

 

[DixieMtCR]

Since you have the panels in parallel, shading of one panel should not affect the other four.

Some charge controllers need the source voltage to be as many as 5 volts higher than the battery voltage to initiate charging. Try connecting two panels in series and see what you get.

Haven't had a moment to test that yet but if it does cause the controller to initiate charge, might that mean that these panels might have a better configuration than 5 in parallel?

 

[HRTKD]

Haven't had a moment to test that yet but if it does cause the controller to initiate charge, might that mean that these panels might have a better configuration than 5 in parallel?

Exactly. Unfortunately, you have an odd number of panels. 5s is good, but most likely your controller isn't going to handle the large voltage. 2s2p may be what you have to go with.

Still, something is off if the panel is rated for 18.3 Voc, but your controller is seeing only 11.5v.

 

[DixieMtCR]

Exactly. Unfortunately, you have an odd number of panels. 5s is good, but most likely your controller isn't going to handle the large voltage. 2s2p may be what you have to go with.

Still, something is off if the panel is rated for 18.3 Voc, but your controller is seeing only 11.5v.

personally I think the charge controller is defective. It's brand new and there is a possibility that it could be defective dead on arrival. because I need to get this system up and going I ordered another charge controller and will continue to hassle with the people who sold me the original one to try and get that taken care of.

 

[DixieMtCR]

Exactly. Unfortunately, you have an odd number of panels. 5s is good, but most likely your controller isn't going to handle the large voltage. 2s2p may be what you have to go with.

Still, something is off if the panel is rated for 18.3 Voc, but your controller is seeing only 11.5v.

Yes. Something is off. I read the Voc wrong.

Exactly. Unfortunately, you have an odd number of panels. 5s is good, but most likely your controller isn't going to handle the large voltage. 2s2p may be what you have to go with.

Still, something is off if the panel is rated for 18.3 Voc, but your controller is seeing only 11.5v.

I read the Voc wrong!

 

[DixieMtCR]

Exactly. Unfortunately, you have an odd number of panels. 5s is good, but most likely your controller isn't going to handle the large voltage. 2s2p may be what you have to go with.

Still, something is off if the panel is rated for 18.3 Voc, but your controller is seeing only 11.5v.

It's very interesting that with a brand new battery that is a 12 volt battery and it is fully charged I have charged it with a house charger That's also new and have used it before and it works fine The controller tells me that the voltage at the battery is 12.8 volts. It also tells me that the charge level on that battery is only 62%. It's almost like the controller is stack and thinks it's a 24-volt battery instead of 12. I have not hooked up the panels to it again today but just the battery to see how it responds to the batteries. No difference it's still crazy. Panels are not even connected so the panels are not the problem.

 

[snoobler]

SCC report SoC purely based on voltage. It likely regards the float voltage of around 13.5V as 100%. A fully charged 12V will settle to the high 12s after charging is terminated and are still fully charged. 62% is not a surprise. The % is not meaningful and shouldn't be used.

24V batteries are dead dead empty at 21V, so your theory regarding 12/24V is not viable.

The data you have presented does not cast any suspicion on the battery.

Until you attach a panel in full sunlight and establish function thereof or not, you're just guessing.

 

[DixieMtCR]

Exactly. Unfortunately, you have an odd number of panels. 5s is good, but most likely your controller isn't going to handle the large voltage. 2s2p may be what you have to go with.

Still, something is off if the panel is rated for 18.3 Voc, but your controller is seeing only 11.5v.

Are you saying that it might be best to connect 2 sets of 2 in series and then parallel those to sets. That would be 4 panels in use. Just not use the 5th panel or find another use for it?

Currently I have 2 panels paralleled, feeding the charge controller. After I gather some data, I will see if 2 panels in series will make any difference.

Currently, this $1500 project turns out to be just a 200ma-300ma trickle charger. This is not a system to power conveniences of the city folks. I left 2-100w equivalent (17w each actually for 34watts) LED lamps on all night. Tomorrow morning I will see if they are still on. And, will the system even charge my 400ah battery bank during the day to light the lamps again tomorrow night? If it cannot generate 340 watthours of power, that is pretty lame!

So, a pointed question. Is this really the best that a 500watt, OFF-GRID, 5-100W panels, 40a MPPT controller can do?

The picture below is the BEST it did today!

 

[MisterSandals]

Is this really the best that a 500watt, OFF-GRID, 5-100W panels, 40a MPPT controller can do?

Looking at the MT-50, your battery is fully charged at 13.6v and your 40a MPPT SCC has pretty much stopped charging as it is supposed to.
The time to see what your controller can do is when the battery is low and the sun is high.

 

[mikefitz]

To confirm the solar controller is defective, disconnect the single panel from the controller and connect the panel direct to the battery. The battery will initially 'pull down' the panel volts to battery volts, then the battery voltage will rise as current flows into the battery. Do not leave unattended and continually monitor battery volts. Terminate the test when the battery volts read 14.4 volts. Being able to measure current flow into the battery would be useful.
A single panel could be tested by measuring its OC, (unloaded) voltage, should be 20 to 23 volts, any lower would sugest shading or very low sun intensity. To measure the SC current set the meter to measure current on the 10 amp range and connect to the panel output. The measured current will be under 5 amps. The current produced will vary with sunlight.
The controller may be defective or their could be a wiring error, when connecting up the controller the process is battery first then the panels, disconnect in reverse. The solar controller is a clone of the Epever range of controllers.

Mike

 

[HRTKD]

Echoing what others have said, if the battery is fully charged, the solar charge controller isn't going to do much.

 

[snoobler]

Easy way to test panel output when battery is full charged is to apply a load in excess of your panel wattage.

 

[DixieMtCR]

Looking at the MT-50, your battery is fully charged at 13.6v and your 40a MPPT SCC has pretty much stopped charging as it is supposed to.
The time to see what your controller can do is when the battery is low and the sun is high.

I should have included a battery screenshot in my previous post too. Battery voltage at that time was 12.4 and current was 200 mills. The PV voltage screen made it look like the battery was full.

 

[snoobler]

Was the panel in full sunlight and perpendicular to the sun?

 

[DixieMtCR]

Was the panel in full sunlight and perpendicular to the sun?

Perpendicular but rained off and on all day. 50% bright sky with no shadows

 

[snoobler]

I would expect more than 2W, but until you get direct sun on it, you can't be sure.

Have you used an ammeter to test the panel current?