Trying to get EG4 6500 EX to reconnect to batteries

[mikeyoungvcu89]

I've been working on this off and on for a while. I have the 6500 and I'm using 2 different non-EG4 LifePo batteries at an unattended cabin. If I get enough cloudy days the batteries reach disconnect voltage and once that happens the 61 error shows up on the inverter and stays that way until I power off the whole system...Shut off the solar, then hit the reset on the battery. I'm not really sure if its supposed to do that or not. I figured that once I got a sunny day the panels would start producing enough power to charge the batteries and bring them out of disconnect status but it never happens....unless I fire up my generator with my EG4 chargeverter, then he 61 goes away the batteries come back to life and all is well. I guess that's because the Chargeverter bypasses the inverter, the inverter then realizes the batteries are back online and is back in business. I got the Chargeverter because charging by generator didn't really work right either.
Is there some setting I'm missing to get the inverter to reset when solar is back ? I thought the answer was to try to connect the batteries with the communication cable and change the battery type from USE but I got nowhere with that.
The other option I thought of was if I could get a standalone solar charger that would bypass the inverter and charge the batteries but that seems crazy as then my EG4 AIO is only an inverter.

 

[timselectric]

It sounds like the battery is disconnecting before the inverter shutdown.
Set the inverter to shutdown before the battery does.

 

[mikeyoungvcu89]

It sounds like the battery is disconnecting before the inverter shutdown.
Set the inverter to shutdown before the battery does.

Yes, I figured that was the easy resolution but it doesn't seem to be working. Either that or the inverter shuts down but the battery continues to drop and then shuts down as well. Battery discharge termination is 43.2 I have the inverter set at 48. The battery supposedly hibernates after 48 hours of no discharge.

 

[Adam De Lay]

Error 61 is when the inverter is set to use battery comms and cannot communicate with the batteries anymore.

If your inverter does turn off before the battery does, I guess ultimately it depends on how long the battery is still running till the sun comes up? Once you get lower than 48v, voltage starts to drop quickly because that's at the lower end of the discharge curve.

I'll be honest I never tested the "dark start" option where you attempt to have the inverter turn back on with solar when it shuts itself down due to a low battery voltage. I would imagine when you use your generator, the inverter is allowed to recover/reset because it detects the battery voltage is above the "shutdown" voltage. The problem is your inverter is also your solar charge controller, but the inverter is shut down due to low battery voltage.

Maybe if you use an external charge controller (a small one), that would be enough to recharge the batteries to the point that the inverter could turn back on and take over charging the rest of the batteries?

 

[timselectric]

Yes, I figured that was the easy resolution but it doesn't seem to be working. Either that or the inverter shuts down but the battery continues to drop and then shuts down as well. Battery discharge termination is 43.2 I have the inverter set at 48. The battery supposedly hibernates after 48 hours of no discharge.

The battery should not discharge much after the inverter shuts down.
In fact it should recover to a higher voltage.
Is there any other loads connected to the battery?

 

[marionw]

Inverters may have two settings that determine when the inverter shuts down AC Output (inverter itself does not shut down). There may be settings for SOC% and/or Voltage.

Check the inverter settings that determine when the inverter kills the AC output then the only load should be the inverter idle current. Make these settings high enough that inverter idle current will not draw down the batteries to where the BMS shuts the battery down.
From time to time depending on the battery charge/discharge cycles you may have to manually charge the batteries to ensure they are FULLY charged.
SOC as reported by a battery BMS can be very inaccurate depending on the charge/discharge cycles. The BMS can get way out of wack with respect to what it thinks true SOC is. The BMS will reset what it thinks is 100% SOC once the battery is fully charged to the point passive balancing starts to occur.

 

[42OhmsPA]

Yes, I figured that was the easy resolution but it doesn't seem to be working. Either that or the inverter shuts down but the battery continues to drop and then shuts down as well. Battery discharge termination is 43.2 I have the inverter set at 48. The battery supposedly hibernates after 48 hours of no discharge.

48V is nearly dead for lifepo4. I'd bump the inverter cutoff up around 50V.

I'd bet the inverter consumption is still a fair amount even when 'off', which would cause the batteries to continue to drain. You can compensate for this by increasing the inverter cutoff.

Thinking out loud, hope it helps.

 

[timselectric]

It's possible that the cells are way out of balance. Or you may have a bad cell.
Which is causing low cell voltage cutoff.

 

[Adam De Lay]

Inverters may have two settings that determine when the inverter shuts down AC Output (inverter itself does not shut down). There may be settings for SOC% and/or Voltage.

This inverter only has 1 option.

https://eg4electronics.com/backend/wp-content/uploads/2022/07/EG4_6.5_Manual.pdf

 

[EG4_Jared]

I've been working on this off and on for a while. I have the 6500 and I'm using 2 different non-EG4 LifePo batteries at an unattended cabin. If I get enough cloudy days the batteries reach disconnect voltage and once that happens the 61 error shows up on the inverter and stays that way until I power off the whole system...Shut off the solar, then hit the reset on the battery. I'm not really sure if its supposed to do that or not. I figured that once I got a sunny day the panels would start producing enough power to charge the batteries and bring them out of disconnect status but it never happens....unless I fire up my generator with my EG4 chargeverter, then he 61 goes away the batteries come back to life and all is well. I guess that's because the Chargeverter bypasses the inverter, the inverter then realizes the batteries are back online and is back in business. I got the Chargeverter because charging by generator didn't really work right either.
Is there some setting I'm missing to get the inverter to reset when solar is back ? I thought the answer was to try to connect the batteries with the communication cable and change the battery type from USE but I got nowhere with that.
The other option I thought of was if I could get a standalone solar charger that would bypass the inverter and charge the batteries but that seems crazy as then my EG4 AIO is only an inverter.

With the error 61, the inverter is losing BMS communication with your LifePo4 batteries. I would recommend setting the inverter to a user-defined state with the low DC cutoff, Float, and Bulk values applied from the battery spec-sheet to see if the issues persist.

 

[marionw]

What is the Make/Model of the batteries?
Do you have any software that you can use to view each battery, it's cell voltages and any battery/cell alarm conditions?
You will first need to FULLY charge the batteries. Just because the BMS "thinks" the batteries are at 100% SOC they may not be as you have cells that are significantly out of balance.
Get the batteries FULLY charged.