Challenges with charge settings - Schneider and EG4 batteries

[OffGridMike]

I am having a heck of a time getting my settings where I want them with my Charge Controller and Inverter. Looking for suggestions.

My system:
Xantrex XW 6068 hybrid 120/240 60 inverter/charger
Conext MPPT 60 150 solar charge controller
4x 48V100ah EG4 LiFePower4 batteries
connected with the EG4 communications hub to an Insight Home communications hub

The problem I am having now is that I keep getting DC overvoltage warnings and faults. My batteries run down to about 90% overnight. In the morning, the sun comes up and recharges. Once they get to 100%, the charge controller seems to put out too high voltage to the inverter and it faults.

I keep hoping the settings will auto-populate correctly with the communications hub, but no dice. When I try to manually change the settings to match the diagrams in the EG4 battery setup guide, they revert back to the default.

I will start with a couple questions I assume are easy.

1) Why can't I update the battery type and charge cycle? When I change them to Li-Ion and External BMS, they go RED after I hit apply. They revert back to Custom & 3 Stage.



2) What setting can I adjust to limit the voltage on the MPPT Charge Controller? I think I need to set a limit of ~57.1 but it keeps sending out more than 58. These are settings for my charge controller.

 

[OffGridMike]

It is currently charging. Here is what the charge controller looks like

 

[OffGridMike]

Here is my inverter

 

[OffGridMike]

I dropped the charge controller down to 56.5v and the High Battery Cut Out on the Inverter to 59v. seems to be working through the scenario that has been faulting previously. Batteries transitioned to standby (fully charged) and the charge controller is powering the load. That is where it was going over voltage in the past. Crossing my fingers.

 

[hwy17]

I use mine with 55v bulk/boost and 55v float. It's unorthodox, but maybe a helpful reference that these higher voltages aren't always necessary.

 

[Old_Skewler]

I have a similar system and it seems like your charging settings are too high for the EG4 specs.

I recommend you read the EG4 specs and set your charger to those voltages. For me, I had to reduce even more the setpoints because of overvoltage errors. IIRC they list 56.2V for bulk but I ended up with 55.2V charging voltage & 15A per pack \, 45A total for my (3) EG4 - in the winter I may increase current if necessary. I've played with 55.5V but occasionally I was getting overvoltage issues.

Regarding the battery type and BMS, I would not try setting it up with BMS control. You still can have BMS communication with the Conext system but I would first manually setup the system for the correct voltages. Stick to custom and 3 stage, get the voltages correct, consider also limiting charge current. Once you have determined the correct voltage, try increasing charging current if still needed to achieve 100% SOC but no overvoltage issues.

 

[OffGridMike]

Everything I can tell, my battery settings are fine. The challenge I see is getting my Charge Controller MPPT to stop sending high voltage directly to my inverter when the batteries are charged. When charging the batteries, the DC voltage is right in line with the charge settings. Once they hit 100% and go into standby, the PV input is being converted by the MPPT to supply the inverter the power to support the load. That is when it is going over voltage.

You can see from the screenshots below, the output is currently 57.4 V but the charge settings all stop at 56.5 V. How do I limit the Charge Controller to stay below 57?

 

[hwy17]

Once they hit 100% and go into standby

I don't think this is a thing. The batteries should not be going into standby.

Your float voltage is unusually high is a concern with this configuration.

 

[hwy17]

If your batteries BMS are going into charge disabled mode then you're going to get weird effects like the MPPT losing control of its output voltage. It needs to be connected to the batteries to control itself normally.