Hi all… trying to understand the alarms I’m getting.
My system is made up of:
a solar collector of about 10kWp,
two Victron Multiplus II 48/5000/70-48 inverters (master+slave)
two Victron 450/100 MPPT
a Cerbo GX
Dyness battery bank with 21.6kWh total capacity, 6 modules
Every morning when battery bank is empty (10%) I am getting this alert:
ALERT Low battery on VE.Bus System - [276]
The alert is repeated several times every morning, until the SOC rises due to solar production.
SOC does not go down under 10%, so I consider that the system is working well.
My original adjust of parameter “Settings/ESS/minimum SOC (unless grid fails)” was 10%. With that setting the alert was firing at 10% SOC.
I tried to modify this parameter to 15%, and now I get same alerts but when battery is at 15%. And SOC does not go down under 15%. So this solution does not work to get rid of this alert.
I have the parameter “device list/multiplus/alarm setup/low bat voltage” set to “alarm only”
What is the correct way to configure the system to get rid of these alerts?
So from what I’ve experienced with my own system is that the BMS will trigger low soc based on voltage and soc. I have my system set to 0% soc and have added a 10 second delay to the low voltage trigger.
It can be configured, but there appears to be 3 elements involved. The ess system, the dbus, and the BMS. Where I can delay the trigger to the dbus, the ess on the inverter seems to get this reading through voltage sense as well, making my bypass only work sometimes.
Essentially, I think we need to modify the firmware to disregard voltage sense. This is probably an artifact from the victron BMS that ensures that the degraded state is not triggered automatically.
But I know much too little about any of that to actually be able to help.
At low SOC your battery voltage will be dropping under load, not uncommon if you insist on deep discharge levels.
You probably have set the low battery prealarm on the inverters and the battery is dropping below this, if it was ESS it would behave differently.
Adjust the pre-alarm accordingly, you can check what the inverter is seeing the voltage drop to.
I have a confusion about the parameters you are asking…
Matthias: when you ask my settings in the MultiPlus and the ESS assistant, are you speaking about parameters I record with the PC app “Ve.bus quick configure”? If so, here you have:
Some time ago trying to get rid of this alarm I lowered pre-alarm values, with no success. I think I tried to reduce pre-alarm as low as 44V.
Parameters of ESS assistant are as follows:
Battery system: System uses LiFePo4 with other type BMS
Battery capacity: 450Ah
VEConfigure battery type selection: Do not change battery type
Sustain voltage: 49V
Dynamic cut-off: all values = 46V
Restart offset: 2V
PV Inverters: No
This morning I measured the voltage of battery when it was giving the alarm. With the tester the lower value I saw was 46.70V (but the app said 46.39V instead, maybe just different measurement points along the battery connection). Obviously if there are short transitions when loads connect (and voltage drops further) I am not able to see these with the tester.
Do you think that my parameters are OK? Any test I could do?
Hi Matthias, I have a Dyness B3 x 6 bank, and I think it is a 15S but not sure…
But apart from that… I think that you pointed me in the right direction, thanks for that.
All manuals I have read about configuration of dyness batteries with Victron told me to put in the ESS assistant certain set of parameters, and so I did. But after reading and understanding what ESS assistant is telling us, I think these parameters may be wrong. That’s what I understood:
If we use ESS assistant, the parameters in tab “Inverter” (DC input low shut-down/DC input low restart/DC input low pre-alarm) simply do not apply (Good to know!)
What applies using ESS is “dynamic cut-off”
“Dynamic cut-off” + “Restart offset” is actually what will be used to fire the low bat pre-alarm
Well, with that in mind, and seeing that when my battery bank is at 15% it has a voltage around 47V, I will try to adjust dynamic cut-off at 44.50V and restart offset = 2V. This should fire the pre-alarm at 46.50V. Right?
Please Matthias, if you could just confirm that I understood well all this…
That battery seems to be 15S.
With a 15S battery I would look at the recommended settings for Pylontech:
47V is not 15% that’s less than 10% more likely less than 5%.
I just looked at one of our systems with Pylontech, yesterday that system discharged the batteries to 10% at the moment it stoppt discharging with ~33A the voltage was at 47,6V.
When was the last time the batteries were at 100%?
