Hey guys,

So in the early hours this morning my 3x Pylontech 2000s ran down to 25%.

This is nothing new, however, i received an "Battery Low" alarm, then an "Internal Error" alarm. The entire system then shut down.

Seeing though it was 25% and around 1 hour till it starts charging, i did a system restart, and it all switched on for about 1min and the same thing occurred. I looked at my three pylons and noticed the master had a red light glowing. I did another restart and looked at what happened.

1. Switched all thee off
2. Switched all three on
3. Master goes into master mode and all the lights on master switched on
4. All lights on second switch on
5. All lights on third switch on

This is all normal behavior.

I checked my venus and saw batteries are on 25% then all of a sudden venus reports no batteries I get the "Low Battery Alarm" and the master once again has just a red light glowing.

I disconnected the PV modules and then did some fault finding by removing the third battery out of the series. Same thing as above happens.

I tried it with only the master and same thing happens, so i figured it was my master battery that is having issues. So i decided one last test. I moved the master battery to the bottom of the stack so my 2nd battery was no effectively my master and i configured it appropriately. I restarted the system and everything seems OK now. even the old master battery is now charging fine. The system is running smoothly.

So i have a few questions:

1. Has anyone had this before where a battery seems fine but does not want to work in master mode?
2. I dont like to assume stuff, but would it be fine to keep em running as is, seeing though there is no longer an error being thrown?
3. My assessment and end result leads me to believe there is a problem with the "orriginal master's" BMS. Is this even possible?
4. I looked at my venus gx and under the pylons it now shows that my State of Health is 99% where it was always 100%. The batteries are 6 months old and i it very seldom happens that i go below 20%, it only happened a hand full of times. how quickly does the state of health drop on these pylons?
5. The below screenshot shows the error as logged in VRM, is there any way for me to get detailed info from the pylontechs or from the venus device?

 

Edited June 2, 20197 yr by stoic

Don't know about Pylontech, but I know with LG batteries an internal error could mean there is cell imbalance. So just giving them a full charge and holding it up there for a bit so it can balance and recalibrate might well resolve the issue.

@stoic

How about to connect the console cable, laptop, and check the Pylons with their native software?
https://powerforum.co.za/topic/2322-youdas-off-grid-lab/page/2/?tab=comments#comment-53641

 

2 hours ago, Youda said:

@stoic

How about to connect the console cable, laptop, and check the Pylons with their native software?
https://powerforum.co.za/topic/2322-youdas-off-grid-lab/page/2/?tab=comments#comment-53641

 

I'll need to get some serial connectors first  

This makes me think ... if Venus can get info over CAN, then i should be able to get the info too.

2 hours ago, plonkster said:

Don't know about Pylontech, but I know with LG batteries an internal error could mean there is cell imbalance. So just giving them a full charge and holding it up there for a bit so it can balance and recalibrate might well resolve the issue.

I'll give it a go.

23 minutes ago, stoic said:

I'll need to get some serial connectors first  

This makes me think ... if Venus can get info over CAN, then i should be able to get the info too.

Nope. Pylons are sending just the basic status messages over the CAN. 

With serial interface, RS232 or RS485, there's much more details available...for example individual cells voltage, cells temp, per brick current etc.

I had a long power outage as I was due to go on a two week break. 

I kept on doing the normal household stuff as I thought the pylons would last. But it  was not to be and they shut down. 

My infini super 4k was showing an error 15 earlier in the day and when it shut down it was showing error 13. Before I left the power came back on but the batteries were still charging in my absence. I could not clear the error and the inverter started up by me fiddling with it. I did not have the time to wait and see if it was going to start up by itself. It then started charging but only after I switched the batteries on manually. I just hope it went on to operate normally in my absence. Although now I see an automatic mains / inverter switch in my future. 

The big issue for me is why the invertor is trying to manage the batteries as the bms is operating 100% independently of the inverter. It should totally ignore the battery status and only use it when it is required to do so and when it is switched on. Under no circumstances do I need an inverter that tries to interfere with the working of the pylontech's bms. 

I will let the batteries run down when I'm home again. to see what will happen. 

Edited June 2, 20197 yr by Johandup