I let the smoke out of my MPPT SCC

[JoeHam]

User error as I hooked up the solar panel backwards but not sure how that happened. Either my solar panel is wired backwards or the cables I got are wrong.

Obviously I should have put a meter on to check polarity prior to connecting but I thought the MC4 connection was idiot resistant.

Hopefully someone can look at the photo here and tell me if the MC4 connectors are correct for pos and neg. I bought them pre-made and smoked my MPPT SCC when the battery and solar panels were connected. At the very least a capacitor gassed out and probably more. I do have pictures of inside the unit if that would be helpful. The main board has Welsee Electronics on it.

This SCC was on $70 from Bioenno Power. I will likely order another unless someone can steer me to a 48v MPPT SCC for LiFePO4 batteries. My amperage requirement is low.
At $70 this was not the worst tuition payment to the school of hard knocks I have ever had!

 

[JoeHam]

I should have mentioned that this fiasco was with a 48v LiFePO4 battery.

Pictures of smoked insides:

 

[ghostwriter66]

The only way to check to see if the connections are correct is to connect a meter to it ...

As for SCC i like the EPSOLAR ones -- OR anything thats allows you to put in your own parameters ... LiFePO4 is much easier to program parameters for then other batteries ...

BUT if you let any type of smoke out i would not trust it .. good way to mess you batteries up with a runaway SCC

 

[JoeHam]

Hmmm, i didnt know that mc4 connectors had to be "male positive or male negative"?

I just used whatever one i grabbed but ensured that red cable was attaching to red cable and black....

Well the red cable I have is negative and the black cable is positive with the genders shown in the pic. Please take a look at the pic and tell me if the red cable is opposite whatever you have.

As I stated, wish I had taken the extra minute to find my meter and check before plugging it in.

 

[JoeHam]

The only way to check to see if the connections are correct is to connect a meter to it ...

As for SCC i like the EPSOLAR ones -- OR anything thats allows you to put in your own parameters ... LiFePO4 is much easier to program parameters for then other batteries ...

BUT if you let any type of smoke out i would not trust it .. good way to mess you batteries up with a runaway SCC

I completely agree and wish I had used a meter first as I stated. I also have no intention of trying to fix this $70 SCC.

Would you have a link to the EPSOLAR you use? My first look on Amazon showed this one for nearly $500 and a single one star review:

Amazon.com: EPsolar IT4415ND MPPT 45A Solar Panel Regulator Charge Controller 12/24/36/48v Auto Work LCD Display User Adjustable Settings for Off Grid Battery Charging : Everything Else

Buy EPsolar IT4415ND MPPT 45A Solar Panel Regulator Charge Controller 12/24/36/48v Auto Work LCD Display User Adjustable Settings for Off Grid Battery Charging: Everything Else - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

 

[ghostwriter66]

Well I the red cable I have is negative and the black cable is positive with the genders shown in the pic. Please take a look at the pic and tell me if the red cable is opposite whatever you have.

As I stated, wish I had taken the extra minute to find my meter and check before plugging it in.

So recently we had 6 HQST panels come in -- some pretty big ones -- and HQST is basically Renogy - so pretty good QA ... BUT sure enough -- one of them had their cables reversed -- and thus why we check each and every time ... and of course this is NOT the first time -- with HQST nor most other brands -- ppl get tired or lazy or its Friday afternoon and quitting time -- or maybe just one toooo many at lunch -- either way though -- a $20 meter saves you $100's of dollars of "Teaching" Points ...

 

[ghostwriter66]

I completely agree and wish I had used a meter first as I stated. I also have no intention of trying to fix this $70 SCC.

Would you have a link to the EPSOLAR you use? My first look on Amazon showed this one for nearly $500 and a single one star review:

Amazon.com: EPsolar IT4415ND MPPT 45A Solar Panel Regulator Charge Controller 12/24/36/48v Auto Work LCD Display User Adjustable Settings for Off Grid Battery Charging : Everything Else

Buy EPsolar IT4415ND MPPT 45A Solar Panel Regulator Charge Controller 12/24/36/48v Auto Work LCD Display User Adjustable Settings for Off Grid Battery Charging: Everything Else - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

This is my go-to BUT it only does 12/24 ... see if you can go to google and type in epsolar 48V and see what they have ...

Amazon.com

 

[SolarRat]

It did you a favor as that controller is probably junk. Do not re-buy it. From your first pic I see a bulged capacitor...replace that and it'll probably work again...but do yourself and your battery a favor and get something better.

 

[JoeHam]

It did you a favor as that controller is probably junk. Do not re-buy it. From your first pic I see a bulged capacitor...replace that and it'll probably work again...but do yourself and your battery a favor and get something better.

View attachment 6605

Thanks SolarRat. That is definitely where some smoke and I believe some liquid came out! I will likely just scavenge the aluminum heat sink and a few components for my junk box. The rest will get pitched.

I am already looking for an alternative 48v MPPT SCC and any suggestions are welcome.

 

[SolarRat]

I am already looking for an alternative 48v MPPT SCC and any suggestions are welcome.

I'd go with a Victron, Epever, or Midnite. Decent quality for the $.

 

[nosys70]

MC4 connector have no polarity , since MC4 is one wire only.
but the common sens would be to differentiate the positive an negative by inverting connector (male, female).
generally the female MC4 is associated with the positive.

 

[JoeHam]

This may be hard to believe but I am extremely happy I let the smoke out of my SCC. Unlike @WillProwse I am too frugal/cheap to take apart stuff that works. However, once I have broken something I always take it apart in the hopes of learning something and/or scavenging some parts.

When I looked inside my SCC I saw "Wellsee" stamped on a few parts. That got me on my google machine looking for info. Imagine my surprise when I came across a very Will like teardown of very nearly the same model. And this teardown was done in 2013!

Take a look here:

AMAZING! I learned what a total piece of junk that SCC was. I never got to use it since I let the smoke out while connecting it up the very first time I tried to use it. This was dumb luck simply due to a reverse polarity cable on my solar panel. Despite wasting $70 on that piece of junk controller I am VERY happy it led me to discovering how bad it would have been for my system in the long run. In addition I was reminded to ALWAYS take a minute to check polarities with a meter on a new setup.

Now on to my search for a new MPPT SCC. I have reached out to @IanRoux from USA-MPP-SOLAR.com about their PCM60X and hope to learn that is a good solution for me. Although I have had an off grid ham radio station for years I have always charged my LiFePO4 batteries from the grid at home and am just now branching out into solar charging. This project is in Arizona over the winter months.

In late spring I expect to work on a solar powered boathouse in Ohio that will need sufficient power to run two 120 VAC 3/4 HP motors on the boat lift. At that time I will be looking into using something like the LV 5048 all in one. Long story short I am hoping that experience gained now with a PCM60X will help me with that project as I think they both use the same software management and general user interface.

I look forward to the forum's help and constructive criticism as I get these projects going but I really wanted to let people know about my happy ending to the letting the smoke out of my SCC story.