Charge controller shuts off every few minutes then comes back on

SolarNoah

New Member
we got this all figured out?
Thanks for checking in.

Not quite... after a few back and forths with Renogy (and some more testing) I am pretty sure it is an issue with the charge controller. Renogy wants the unit back for testing, before they give me a new one. I’m relying on it for power now (in an RV), so can’t send it back in for a few months.
For now, I’ve taped over part of a panel and haven’t had the issue since.

I’ll update once renogy does their testing. I’m still under warrantee for another year.
Thanks,
Noah
 

MrAubin

New Member
Hello! I have been having an issue with my charge controller that I have been unable to resolve. Any insight would be very much appreciated.

System (only what's relevant):
  • Two, 300w 24v solar panels in series. 30 amp inline fuse before charge controller.
  • 60 amp renogy rover MPPT charge controller that goes to a 40 amp fuse
  • 12v lithium batteries
  • *everything listed above is running on 10awg wire (using the same wire that came with the solar panels)
  • smart battery monitor

Issue:
  • Batteries charge like normal in the morning. Around mid-day (seems to be when I'm pulling 27+ amps), my charge controller goes into a strange cycle.
    • It charges the battery (usually gets around 90% charged), shuts off (the charge controller doesn't show any warning lights, it just shows that it isn't receiving any sun), then turns itself back on.
    • This cycle usually repeats every few minutes until either (1) the batteries are fully charged, or (2) I block the solar panels to reduce the incoming sunlight.
    • Photo attached showing a few minutes of this on the battery monitor app. Absolutely no power is coming in at the low points. My batteries are just draining. I just didn't have much running when I took this photo.

I have been on the phone with renogy all week and haven't had much luck. So far, I have:
  • checked for loose wires
  • checked for hot wires. The wires coming out of the charge controller and going to the battery were warm, but not hot.
  • messed around with the settings on the charge controller
  • reset the charge controller
  • scoured the internet for any similar issues... but have come up empty!
I have had this system running well for a few months, but recently have moved to a place that gets more sun (I'm in a campervan). I assume this may have something to do with it.

The only things I can think of are:
  • There is an issue with my charge controller. Renogy said this may be the case. I'm under warrantee, so can swap it out if needed.
  • Something with the wiring? Maybe I need to be using a higher gauge? That said, I don't know why this would cause the controller to shut off like this. I know 10awg wire isn't ideal, but I called renogy when I set this up; they didn't seem to think the 10awg wire would be an issue...
  • Something going on with one of my fuses?

Thanks for reading this far! Really hoping someone is able to shed some light on this.

Cheers,
Noah
Looks like the controller is cycling for a minute every minute. That's sounds like proper charging for a certain type of battery have you reprogrammed the controller for what type of cells you are charging ? Is it hitting the high voltage cutoff ? Maybe from your move it needs to be reprogrammed. I'm sure renogy would have asked I guess. And a fuse will either work or not work. Relays bounce back and forth.
 

MrAubin

New Member
Thanks for checking in.

Not quite... after a few back and forths with Renogy (and some more testing) I am pretty sure it is an issue with the charge controller. Renogy wants the unit back for testing, before they give me a new one. I’m relying on it for power now (in an RV), so can’t send it back in for a few months.
For now, I’ve taped over part of a panel and haven’t had the issue since.

I’ll update once renogy does their testing. I’m still under warrantee for another year.
Thanks,
Noah
Sounds like maybe a bad cell causing you to lose your series run I've read some panels can bypass bad cells or shady cells without compromising the rest of the panels in series. Have you tried disconnecting the taped over panel from the run and test the remaining panels ?
 
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