My Goodwe 4850ES inverter has been installed about a month ago. I have 2 us3000c pylontech batteries connected and 10 x JA Solar 385W Mono MBB Percium Half-Cell panels.

All is working exceptionally good for us expect when the DOD is reached. It is set at 90%. Normally we do not reach the DOD because our batteries have about 25% left before there is enough sun in the morning to charge the batteries again. The problem comes when the previous day was cloudy and rainy and the batteries only charges to about 55%. During the early morning hours when the 90% DOD is reached the batteries switch off. It used to be in standby mode but not lately. Now it switches off and nothing happens until I manually switch on the red button (sv switch) on the batteries. I haven't changed setting  except once when testing the "economy mode" in relation to general mode. Currently I am in general mode.

Any advice as why the batteries switches off and does not go in standby mode? 

Why not have the DoD a bit safer, like 5% away from the point the batteries will turn off? Like 85% instead of 90%?

More importantly, make sure the BMC in the batteries is communicating with the inverter. I found where the cable was not plugged in correctly and the inverter basically did its own thing without really knowing the state of the batteries. Basically pulled the batteries dead and they also switched off like yours.

Thanks Tinuva.

I'll try the 85% DoD but I have feeling no matter what DoD I set it it will do the same. My BMS is working good and besides for the DoD hiccup there is always a "normal" BMS status between the inverter and the batteries. 

I am still looking on the internet for possible reasons.

I also noticed that when I have "battery activated" ( in advanced setting (PV Master app)) set too on it will after a few hours show as off again. The inverter makes as click noise as it should for the changes to take effect so I know it accepted the changes.

Could this not be part of the reason that my "battery activated" is always off while it should be on?

So I tested the scenario again and my batteries switched off last night when the 89% DOD was reached. I had to manually switch on the batteries this morning. 
This is frustrating. If I go away for a weekend and as things stand my batteries won’t charge. 

As per the guide ;

"Battery Activated: Used when lithium battery switch off because of low voltage. But for some battery like LG, should switch on battery switch manually first."...This is to recharge depleted batteries. 

Are you sure you are not taking your batteries too low, try a DoD of 79%, SoC 21%, then see if the batteries still turn off? They are only supposed to go to 80% DoD under normal operation.

Edited May 20, 20215 yr by FixAMess

31 minutes ago, FixAMess said:

As per the guide ;

"Battery Activated: Used when lithium battery switch off because of low voltage. But for some battery like LG, should switch on battery switch manually first."...This is to recharge depleted batteries. 

Are you sure you are not taking your batteries too low, try a DoD of 79%, SoC 21%, then see if the batteries still turn off? They are only supposed to go to 80% DoD under normal operation.

I am going to try that and set the DoD to 79% and see what happens. 
 

Strangely, yesterday morning at 11am the DoD of 89% was also reached and the batteries did not switch off. Instead it was in standby mode for about 30 minutes until the load subsided and started to charge again. 

 

Just to make sure. Do I set the “battery activated” to on or leave it off?

 

1 hour ago, iWatts said:

Just to make sure. Do I set the “battery activated” to on or leave it off?

 

You can leave it on but theres no point if you are only taking your batteries down to 80% DoD.

Have you got batterview.exe to look at the state of your batteries? You will also need a special cable to link your pc to the batteries.

You can then go look at the errors, issues with each battery on a cell level....

Edited May 20, 20215 yr by FixAMess

No I don't have batterview.exe. I'll search around on the web and see what info I can get.

Here it is; https://www.dropbox.com/s/sng0rotu6pjjk78/BView.rar?dl=0

52 minutes ago, FixAMess said:

Here it is; https://www.dropbox.com/s/sng0rotu6pjjk78/BView.rar?dl=0

Thank you

@iWatts, did you manage to resolve this issue? I have just installed my system and having the same issue. I get to roughly 89% DoD and then the inverter changes back to utility (controlled by ICC).

I’ve changed my DOD to 80% on grid and to 90% off grid. This seems to have resolved my issue. 
Still not sure why my batteries switched off at 90% DOD on grid considering the batteries can go to 95% DOD. 

you need a special cable for pylontech  C battery bms coms, not the one in the box

Goodwe Flyer.pdf Note US2000C&US3000C- Dip Switch & Cable Pins.pdf

Thank you for sharing the information.