Charge controller stopped working

[Biggkidd]

Well after 10 or so years of FLAWLESS operation my midnite solar classic 150 charge controller quit working. I'm guessing it overheated. I got the new fans but never heard the old ones make anymore noise so I hadn't changed them yet. Dumbass me now it's going to cost me... I just finished replacing the fans and reset it to factory specs and nothing. It's powered up power is incoming but not out going to the batteries. If anyone has experience repairing these or similar items please speak up. I don't have a clue, electronics are not my strong suit!

 

[Biggkidd]

I swapped the broken charge controller out for the cheap-o new one I bought for up at the shop. It's working. I need to get more panels up ASAP but this is all this smaller cheaper controller can handle. At least we are charging again. I like to have never got it hooked up everything is so small and delicate compared to the midnite solar. I had to split my 6 gage wire into two to hit two terminals designed for much smaller wire. I need to go reconfigure the panels for higher voltage this controller doesn't much like the lower voltage the way I have it setup now.

I have an Email into Midnite solar about my controller hope to hear back from them next week.

Hot and butt kicked. I think I am done for today! Well until tonight anyway. lol Provided I can move then...

ETA:

Went back and reconfigured the wiring to match this charge controller better. Now I really am done until tonight. I've got the cramps happening again, oh joy.

 

[Biggkidd]

Just in case anyone is interested this is the elcheapo charge controller I am using while my midnite solar that lasted over 10 years is down for repair.

https://www.ebay.com/itm/144008903868?hash=item2187997cbc:g:y-gAAOSwTVpgd6Ze
This is the first problem I have had with the midnite solar and it's truly my fault. I heard the fans going bad and didn't repair it when I should have even though I had the fans here. They stopped making the noise so I kinda forgot...

 

[Neb]

Just in case anyone is interested this is the elcheapo charge controller I am using while my midnite solar that lasted over 10 years is down for repair.

https://www.ebay.com/itm/144008903868?hash=item2187997cbc:g:y-gAAOSwTVpgd6Ze
This is the first problem I have had with the midnite solar and it's truly my fault. I heard the fans going bad and didn't repair it when I should have even though I had the fans here. They stopped making the noise so I kinda forgot...

If it really due the heat the components on the heat sink are suspect.

But it you aren't into electronics to figure which one have the heat conducting paste and carefully with the thin mica insulators you should send it out for repair or by 2 replacements.

One to get working again and a second as a backup.

Ben

 

[viking]

From what I've heard, Midnite controllers were good. We are using a MorningStar, TriStar MPPT 60 amp controller we bought when we went to Grape Solar in Eugene, Oregon, they had that solar controller in stock and we saved hundreds by picking up the solar panels and the controller, rather than having it shipped to our home. The MorningStar,
TriStar MPPT controller has very large cooling fins and even on a heavy charge day, the fins stay really cool. The controller is good for up to 150 DC and by changing dip switches, the output voltage is 12, 24 or 48 volts DC, the total solar wattage going to the controller is 1,560 with solar voltages up to 82 volts, with around an available 32+ amps.

 

[Biggkidd]

I think ten years without so much as a hiccup was great. I am also sure I should have replaced the fans the first time I heard them. I've had them here awhile. Unfortunately this is not an item I can just buy took me a long time to save up for the first one. I am glad I had something I could use though. Repair parts are expensive too but they are the best charge controllers in my opinion and worth fixing or replacing even at the cost they are. This one can do up to 150 volts PV upto 94 amps or about 5000 watts @48 volts IIRC. It's a Midnite solar classic 150 if anyone wants to see the specs. Really well made, Made in America I do believe! So it's quite the piece of equipment. Also it adjust for voltage 12 24 48 automatically. A replacement control board is right at $250 and the power board is $300 I'm hoping the good folks at midnite can point me in the right direction.

 

[Biggkidd]

Don't feel up to doing anything today so I'm resting and keeping a watch on the power levels and how the new controller is doing. It seems to be working well even if a little strangely. Making 2300 watts out of 2400 watts worth of panels which is really good but the PV voltages are kind of all over the place. Which I am not use to seeing so much. Minor rapid changes sure couple points here and there but these are big rapid changes 20-30-40 volt swings. Just seems strange.

 

[Biggkidd]

Holding pretty steady between 2300 and 2400 watts so no complaints in that department.

 

[Biggkidd]

Guessing the meter on this charge controller isn't accurate seeing as it says I am making 2600 watts with only 2400 watts worth of panels. It was also getting warm / hot enough I put a fan blowing on it. The sun is now directly overhead and hitting the panels straight on...

 

[viking]

Last summer I used a small fan aimed at the solar controller and back of the inverter, just to stop any pooling of hot air, that probably wasn't necessary but I like to have electronics run as cool as possible, both the Magnum Energy inverter and the MorningStar solar controller have very good self protective systems that will drop them off line when the voltage or amperage are not within design parameters and will reset themselves, all I have to do is delete the default information. The biggest job I have to do is keeping the GC-2 battery electrolytes topped off.

 

[Supervisor42]

. The biggest job I have to do is keeping the GC-2 battery electrolytes topped off.

Take a close look at the float voltage.
Most charge controllers are set up for AGM or SLA batteries. Their float voltage is around 2.5 VPC (volts per cell).
Flooded batteries are much happier with 2.2 VPC or maybe just a little bit less to maintain them at 100%.
It won't hurt the lead-acid batteries to maintain them at the higher voltage as long as the electrolyte is maintained above the plates.
But it will keep you busy with the water bucket.
The float voltage is not to be confused with the 'gassing voltage' flooded batteries see during the end of a recharge cycle.
There is a procedure for determining the correct float voltage of flooded batteries because it is different for every manufacturer due to different plate chemistry.

Now back to dead semiconductors in a failed controller...

 

[Neb]

Take a close look at the float voltage.
Most charge controllers are set up for AGM or SLA batteries. Their float voltage is around 2.5 VPC (volts per cell).
Flooded batteries are much happier with 2.2 VPC or maybe just a little bit less to maintain them at 100%.
It won't hurt the lead-acid batteries to maintain them at the higher voltage as long as the electrolyte is maintained above the plates.
But it will keep you busy with the water bucket.
The float voltage is not to be confused with the 'gassing voltage' batteries see during the end of a recharge cycle.
There is a procedure for determining the correct float voltage of flooded batteries because it is different for every manufacturer due to different plate chemistry.

Now back to dead semiconductors in a failed controller...

Oh

Is it time to start guessing?

I guess a fried IGBT on the heat sink.

Ben

 

[Supervisor42]

Oh

Is it time to start guessing?

I guess a fried IGBT on the heat sink.

Ben

I think a bunch of MOSFETs got into a shooting contest and everybody lost. I saw that in several inverters.

 

[Biggkidd]

I am using AGM batteries by Absolyte 2 volt cells to be precise.

Heard back from Midnite solar today they said send it in and it would likely run about $200 to repair. Which is a lot less than a new one or buying and replacing the boards in this one. Electronics are not my fortay!

It has a whole string of MOSFETS running all down one side.

 

[Biggkidd]

Okay so I finally have the cash to replace my midnite solar controller or get the old one fixed. Or I could get a new one ordered this week and next month send my old one in for repair. Which is the direction I am leaning. But now there's a third option of buying this

https://www.renogy.com/48v-3500w-solar-inverter-charger/
Which is a larger inverter than ours are with a built in MPPT solar controller. Today I hooked up my older inverter I repaired so now we are running 2) Aims 2000 watt pure sine wave inverter chargers. Which also happens to cover my need for a larger inverter at this time.

Getting a new Midnite solar charge controller and having the old one repaired will cost about the same as the Renogy inverter I linked. The midnite controllers have come down by about 40% since I bought mine a decade ago.

 

[Biggkidd]

Ordered a new midnite solar classic yesterday. I'll feel a lot better once it's here and hooked up. Glad as can be I had this cheap PowMr controller to use in the mean time. Still planning to get our old midnite fixed in a month or two if things hold together that long...