The Q&A guide further states that the voltage is capped at 52.4V, which is already higher than the absorbtion voltage. In reality the system reaches 52.4V, so it seems that the first setting is ignored with Pylontech BMS attached (as DVCC is also set to “Forced on”)?
In some cases, with internally unbalanced Pylontechs (we had this case as 2 of 4 US2000Cs were faulty, and the remaining good ones didn’t reach 100% for longer time because of the faulty ones blocking the absorbtion). So you might also want to reach the 53.2V that Pylontech recommends, at least for a short time, to get such healthy but unbalanced batteries balanced in a reasonable amount of time. Is there a way to configure/set this…?
You could try to set the DVCC controlling BMS to None and then the system will take into consideration the values set inside the inverter - those 52V and 51V if you set them that way.
Thanks! So like setting absorption to 53.2V in the MultiPlus II (the “official” value from Pylontech), and float could stay at 51.0V of course?
Does that mean my assumption is correct, that you can basically set whatever you want as absorption in the MultiPlus - the 52.4V are enforced by Victron as soon as Pylontech is set as the controlling BMS in DVCC..?
More background info: I agree that in a healthy environment you don’t need this, but in some cases or after long periods without reaching 100% SoC it could be helpful. Another example is the new US5000 we received under warranty, it’s healthy but was shipped unbalanced internally. At 52.4V it did simply not balance anymore at all and didn’t reach 100% SoC even after long time, I watched it closely with Pylontech BatteryView. It needed a few discharges/recharges, because only then and with current flowing some cells went above 3.50V and balancing happened (not sure what the exact balancing triggers for the US5000 are though, and US2000C seem to balance better at 52.4V from what I observed).
All Pylontechs are starting to balance when any of the cells are over 3.36V and difference between min and max cell voltages is over 30mV.
Your battery would balance if let enough time…
Maybe it would have balanced at 52.4V after another lots of hours, but on BatteryView it really looked stuck even on the third decimal place…
Anyways, thanks for explaining that the 52.4V are overriding any other configured absorption voltage setting when Pylontech is set as controlling BMS in DVCC, maybe Victron could point that out explicitly in the guide I mentioned initially, because at least to me it was not obvious.
So what are we saying setting are supposed to be as I’ve noticed capacity isn’t as good any more with my 4 us5000’s and before I start my next stack I want these running 100% advice much appreciated and we saying change to no BMS in DVCC for a period of time? @alexpescaru@da901
