Renogy charge controller battery over-voltage alarm

mpickus

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Renogy Rover 100 charge controller periodically sounds a "battery over-voltage" alarm. While the alarm is sounding, the Renogy BT app displays voltages as high as 17V (for a 12V LiFePO4 battery) and I get the same reading when I use a voltmeter on the battery terminals. But after a few minutes, the alarm stops, the BT app and voltmeter both show battery at 14.6V. If I disconnect then re-connect the 6 solar panels when the alarm is sounding, everything also returns to normal. The batteries have internal over-charge protection so I am fairly sure they are never actually charged to 17V. This issue seems to happen particularly on a partly cloudy day when panels are suddenly hit with full sun. Renogy tech support has not been helpful so far. Two questions: 1) should I be highly concerned about damaging the batteries?? 2) is there any way to prevent this error alarm??
 

Texas-Mark

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Sounds like your charge controller is not working properly. The 17V you measured at the battery terminal was probably after the battery overcharge kicked in and there was no load. I would not trust that charge controller.
 

Bud Martin

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Did you turn off the Batteries Equalization function?
Is the SCC set to auto detect system Voltage or you manually set to 12V?
 

mpickus

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Did you turn off the Batteries Equalization function?
Is the SCC set to auto detect system Voltage or you manually set to 12V?
Charge controller is manually set to 12V. Not sure what you mean by Batteries Equalization function. "Equalize Charge Volt (V)" is set to 14.4V. I do notice that "High Voltage Disconnect" is set 16.0 V which seems way too high. Also "Charge Limit Voltage" is set to 15.5V and that also seems too high.
 

Texas-Mark

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I do notice that "High Voltage Disconnect" is set 16.0 V which seems way too high. Also "Charge Limit Voltage" is set to 15.5V and that also seems too high.
Seeing how you measured 17V, still looks like the charge controller is not working right, or something is not wired correctly.
 

Bud Martin

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Charge controller is manually set to 12V. Not sure what you mean by Batteries Equalization function. "Equalize Charge Volt (V)" is set to 14.4V. I do notice that "High Voltage Disconnect" is set 16.0 V which seems way too high. Also "Charge Limit Voltage" is set to 15.5V and that also seems too high.
The battery Equalize function should be turned off, Equalization should not be used on LiFePO4 battery. You need to lower the 'Charge Limit Voltage' to around 14.5 (3.62V per cell), 'High Voltage Disconnect' to around 14.75V.
 

12VoltInstalls

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Renogy tech support has not been helpful so far.
Typical
Sounds like your charge controller is not working properly.
Hi guys how do you turn off the equalization??
I don’t know that controller but I don’t think it has a LiFePo parameter.
Typically you’d user select AGM/sealed parameters in the ‘user’ menu - if it allows you set the equalize to the same volts as boost you’d do that, or 0.1 volts higher than charging or ‘boost’ volts. (set the equalization time to 0 or 1 minute if it lets you)

Either way 17V is like too high for anything 12V afaik and something isn’t right.

How many watts of panels?
And does this happen after a high-amp load starts up? One funny thing (that I know see others have experienced occasionally) is that when the batteries are full; bright, full sun is present; and a big load starts up - shop vac in my case- the SCC “sees” the sudden load (and interprets or sees that as low voltage) an mppt SCC can spike its output voltage triggering the inverter and (in my case) the charge controller to shut down according to their over voltage settings.
Just brainstorming- not saying this is your issue but it crossed my mind to mention.
 

12VoltInstalls

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Somebody smarter than me needs to correct or confirm these.

Or you could look this up using the search bar for any of the many threads that discuss custom SCC settings for LiFePo cells!

The high voltage disconnect may need to different and still be set higher than the charge limit voltage.
The charge limit voltage is too high
The float voltage may need to lower
The bottom two: over discharge and discharge limit are too low

Not my area of knowledge though
 
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