Hello, there are two different definitions, what will happen, when BMS reaches Discharge floor. See images. One says contactor stays ON, the other one says OFF. Which one is correct, please? I had an accident, when after entering Discharge Floor BMS switched off, contactor opened, and after supplying Multiplus with power Multiplus entered fault mode. This is not the expected behaviour. If yes, I have to modify the system.
I forgot to mention - it is Lynx Smart BMS 500A, with Victron NG batteries and ATC+ATD connected to BP-65.
Presumably a Lynx NG BMS.
I believe that the manual is correct, I have attached a better description from the manual which describes this in detail, Section 4.3 Page 15.
VEConnect is a brief summary and omits the key info that the Contactor stays closed for only 5 minutes and then opens if charging is not started. I will raise the discrepancy with Victron.
Well, then it only duplicates behaviour of standard OFF state, just a little bit “sooner”. Opening ATD, keeping contactor + ATC closed and KEEPING BMS ON is much better way how to behave when Discharge floor is reached.
All my previous BMSs behaved this way when adequatly discharged. I will try to use pre-alarm relay to disconned loads earlier, to see, if it helps. Anyway, if BMS goes always OFF within 5 minutes after ATD limit is reached, that is somehow nonsense.
And reading the manual again and again, there is similar mismatch between “low SoC” and “Discharge Floor” terms. As “low SoC warning” value is definitely not the one, which causes BMS to go OFF. Instead “Discharge Floor” is actually “low SoC treshold.”
I guess I have to connect ATD wire through Alarm relay too, so it will disconnect loads already during pre-alarm to prevent BMS from switching off (after reaching DischargeFloor/lowSOC).
Switching off loads is solvable remotely, BMS OFF is disaster for me via remote (there is no-one onsite to restart it via switch)