3xMulti plus 8xMPPT plus 2xDIY batteries - setup for voltages (bulk, absorption, float)

DIY
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1

Dear Community!

Maybe, you can support me to find the right setup for my “project”.
In a nutshell:
3 Multi (3000) parallel (for each phase) with 8 MPPTs (for the different angles on the roof) and 2x DIY batteries (16 cells per battery) = 48V system.
Setup since January running with changes (to 3 phase setup) in June.
Systems runs perfect and “not”.
Perfect - no additional energy imported form the public net = 99,9% “stand-alone” (Autarkie). No issues, no effort, runs smoth, perfect, 2+ days without any import from public, no export only “own consumption”, …
Not perfect - I know that during the setup of my Multis, I entered a voltage of 56,8 or 58,4? voltage within the ESS setup (3.55V/3.65V per cell = 16 cells).
Now, I want to reduce the voltage during the charging process (bulk and absorption).
I activated DVCC and entered 55,2V for - I guess - it’s charging voltage?
Where can I change the absorption voltage? Within the Multis?

→ I checked via Home Assistant (BMS are connected to Home Assistant) the max voltage and some cell voltages → 3.65V during absorption I would say which is too high why I want to reduce this one to 3.45V (or sth. similar).
During charging - not more than 55V just only a peak after “bulk” up to 56,xxV.
What about float voltage?

Any suggestions, tip’s, tricks?

Thank you and best regards.

2

With such an impressive system, i would suggest reading up / learning all set up parameters, before a setting causes an inciden.
All information can be found on “Victron Energy - Victron Professional”

3

I already did but as I also know, not everything is covered within the documentation (I also got some hints in forums like this one).

That’s why I want to exchange with others to get an idea, how I can change the voltages to reduce the load for the batteries/cells.

4

You need to adjust the settings in the Multipluses using a mk3 VE Bus to USB interface connected to a laptop running Victron VE Configure.

If you have a GX device you can also do remote VE Configure via VRM.

There are things to be careful about when programming parallel and 3 phase.

VE Configure

Remote VE Configure

This is quite involved and care must be taken. There is no simple setting somewhere to deal with this.

1 Like
5

No problem - I used the adapter to configure every Multi (as three phase system + ESS).
Yes, Cerbo also installed.
I’ll check the shared information again and in case of further question, I’ll ask here.