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Midnite Classic 250 switches between mppt bulk and resting

TySonoma

Thai
Joined
Jan 20, 2021
Messages
4
Location
Santa Rosa, CA
Hello,

I am new to the group (and to solar) and I just purchased a DC Solar trailer at auction. The setup consists of 2 SMA Sunny Island Inverters, a Midnite Classic 250, 2 Industrial size FLA batteries, and 10 solar panels all mounted on a trailer. I managed to get the batteries charged up by hooking up a generator to the SI. All seem ok except that I can't get the Midnite Classic (CC) to charge the batteries. All connections are good; I also tested and measured the voltage and current of the panels to the PV combiner box. The problem is that the CC clicks periodically and switches back and forth between mppt bulk and resting but produces 0 watts. The CC displays the correct voltage, but is not pulling any amps to charge the batteries. Do I have a broken CC or am I missing something? Any suggestions of tips would be appreciated.
 

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Welcome to the forum.

Is this one of those Bidindustrial auction trailers? I was tempted. Config H? I just couldn't stomach the risk of dropping $4k.

I would continue to charge the battery with the generator and get it charged up. What skeered me away from those was the likelihood of the batteries being bad due to sitting in a reduced state of charge. You need to rescue the batteries ASAP in conjunction with sorting the controller.

I would double check all the parameters of the charge controller to ensure they are correct for the battery. Disconnect solar panels, disconnect battery, reconnect battery, reconnect solar panels. I would not expect it from a Midnite solar unit, but many SCC manufacturers recommend never connecting the SCC to the panels without battery power applied.

Again, step 1 is get that battery fully charged ASAP. Take voltages at as many places as you can access to look for irregularities.

Good luck!
 
Snoobler, yes, it was at an auction in northern California. I thought the pair of SMA Sunny Island inverters and the trailer alone would be worth it. Thank you for the tips; I will proceed with charging the batteries to full capacity and take the steps you recommended.
 
No question the value was good, but the hassle associated with bad components turned me off... plus, I already have everything I need, and it would just be one more thing I'm hoarding... :)
 
Midnight controllers have coin battery slot in the lid for preserving settings when the power has been cut off. It's possible that the settings might have been corrupted somehow during an incorrect shutdown. In addition to doing the normal shutdown as suggested above, I could also suggest pulling the coin battery to wipe all the previous settings. When you boot the controller back up, you'll have to re-input every single setting.

One final thing I could suggest before calling Midnight is to refresh the firmware with the latest addition. Refreshing Midnight's firmware is a pain because you have to refresh both the unit itself, and the digital display, but that could potentially solve your problem.

But, yes, in the mean time, keep those batteries charged by whichever means you have.

Looking at the manual, there might be another way to do this. Look at page 69.

Do a hardware factory restore. There are 4 sets of jumpers directly above the blue terminal block. For the purpose of this we will call the left most jumper JP1 and the right most JP4 (actually labeled "Boot")
 Step 1- Turn the PV and Battery power off to the Classic and remove the front cover
 Step 2- Locate the 2 jumpers JP1 and BOOT (JP4). Take the actual jumpers and keep them in your hand
 Step 3- Turn the Battery power on to the classic
 Step 4- within 1 minute place jumper JP4 on its two pins and then place jumper JP1 on its two pins. at this point the 3 leds on the top of the circuit board should flash back and forth for about 60 seconds.
 Step 5- After the flashing stops power down the classic and remove JP1 and JP4 and stow them back on a single pin like they where.
 Step 6- Put the front cover on and power up the Classic Lite. If you have the MNLP set to Custom you will need to go to the local app and reset the battery voltage and setpoints etc.
 
Hello Michael,
Midnight controllers have coin battery slot in the lid for preserving settings when the power has been cut off. It's possible that the settings might have been corrupted somehow during an incorrect shutdown. In addition to doing the normal shutdown as suggested above, I could also suggest pulling the coin battery to wipe all the previous settings. When you boot the controller back up, you'll have to re-input every single setting.

One final thing I could suggest before calling Midnight is to refresh the firmware with the latest addition. Refreshing Midnight's firmware is a pain because you have to refresh both the unit itself, and the digital display, but that could potentially solve your problem.

But, yes, in the mean time, keep those batteries charged by whichever means you have.

Looking at the manual, there might be another way to do this. Look at page 69.

Do a hardware factory restore. There are 4 sets of jumpers directly above the blue terminal block. For the purpose of this we will call the left most jumper JP1 and the right most JP4 (actually labeled "Boot")
 Step 1- Turn the PV and Battery power off to the Classic and remove the front cover
 Step 2- Locate the 2 jumpers JP1 and BOOT (JP4). Take the actual jumpers and keep them in your hand
 Step 3- Turn the Battery power on to the classic
 Step 4- within 1 minute place jumper JP4 on its two pins and then place jumper JP1 on its two pins. at this point the 3 leds on the top of the circuit board should flash back and forth for about 60 seconds.
 Step 5- After the flashing stops power down the classic and remove JP1 and JP4 and stow them back on a single pin like they where.
 Step 6- Put the front cover on and power up the Classic Lite. If you have the MNLP set to Custom you will need to go to the local app and reset the battery voltage and setpoints etc.
Michael,

Thanks for the tips. Will proceed with all your suggestions and post the results

Thai
 
Did get the unit fixed by contacting tech support and shipping the unit back for repair. Amazingly smooth experience with the process of getting the unit shipped to Washington and back. Everything works now, and the repair cost was more than reasonable. Only wish that all my tech support calls and RMA processes were HALF as good as MidNite Solar! Kudos to all at MidNite Solar!
 
And this is exactly why i have MidNite gear......once i called MidNite tech support and Robin answered.....I was so taken off guard I mumbled “the Robin” he answered yes, i was just down here and grabbed the phone, just like its an everyday thing. Where else will a corporation’s president answer a new users call....lol
 
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