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diy solar

3x 100A BMS (problem with Multiplus discharge) or 1x 300A BMS?

Alarchist said:
Hey @DutchCookieMonster I'm not sure on 3phase or ESS setup, but if you have 3 x BMS are you using:

https://github.com/pulquero/BatteryAggregator or similar, to aggregate each BMS/Battery? Allowing the Multi's to charge/discharge with full current for all 3 batteries combined, If not then that might be part of your problem.

Side note:

If you have a shunt too, but want to use the BMS for battery monitoring, you'll need to SSH in and run "dbus-spy" on command to see what bus the shunt is on, the battery aggregator read me is useless, but it works well. When it says to exclude a shunt add "excludedServices": ["com.victronenergy.battery.shunt1"] you need to swap the 'shunt1' part with tty7 or whatever bus dbus-spy showed it on.
Click to expand...
I had already read about BatteryAggregator. But hesitation to carry it out. (due to the experimental phase) I'm going to run the recommendation of ESS dynamic cut off settings first. After that, I'm going to try other options.
 
DutchCookieMonster said:
I had already read about BatteryAggregator. But hesitation to carry it out. (due to the experimental phase) I'm going to run the recommendation of ESS dynamic cut off settings first. After that, I'm going to try other options.
Click to expand...

Can you share your VRM? You can see mine in my signature. VRM should help confirm the cut-off is happening at 52V.
 
DutchCookieMonster said:
I had already read about BatteryAggregator. But hesitation to carry it out. (due to the experimental phase) I'm going to run the recommendation of ESS dynamic cut off settings first. After that, I'm going to try other options.
Click to expand...
If you can install dbus-serialbattery then batteryaggregator shouldn't be a problem, maybe share your .config file for serialbattery that could be overiding ESS settings.
 
sunshine_eggo said:
Please.
Click to expand...

You asked for BMS config, not serial battery config. OP showed Overkill BMS config screenshot. I missed OP's response initially, but not clear to me. The default config for serial battery also has some funky settings that need adjusting for full charge and discharge under normal use. Is it beta or latest, have they messed the config file up by mistake, all related questions to serial battery config file that could cause the problems.

Please.
 
Last edited:
DutchCookieMonster said:
The problem I have is that the Inverters (3x Multiplus 48/8000 (3Phase) stops wit discharge (Idle) between 45% an 55% of the battery capacity.
Click to expand...

If the rest of the Serialbattery .config file is default settings, and you don't have a battery aggregator, then probably the serialbattery driver is telling the Cerbo to reduce charge / discharge limits.

See the settings below from the default.config file, if it's cold or hot, or if only one battery is recognised, the limits will apply as a fraction of that single battery.

The VRM token was invalid, for me to view your VRM. Can you look at the charge / discharge limits in the advanced tab widgets, that will show what's happening, should look something like this:

Screenshot 2023-12-23 152716.jpg

Here's just a few of the many things that can affect charge / discharge from the serialbattery default.config file, might be worth going through it again to see if something is limiting the Multi's:

; --------- Cell Voltage Current limitation (affecting CCL/DCL) --------- ; Description: Maximal charge / discharge current will be in-/decreased depending on min and max cell voltages ; Example: 18 cells * 3.55V/cell = 63.9V max charge voltage ; 18 cells * 2.70V/cell = 48.6V min discharge voltage ; But in reality not all cells reach the same voltage at the same time. The (dis)charge current ; will be (in-/)decreased, if even ONE SINGLE BATTERY CELL reaches the limits ; Charge current control management referring to cell-voltage enable (True/False). CCCM_CV_ENABLE = True ; Discharge current control management referring to cell-voltage enable (True/False). DCCM_CV_ENABLE = True ; Set steps to reduce battery current ; The current will be changed linear between those steps if LINEAR_LIMITATION_ENABLE is set to True CELL_VOLTAGES_WHILE_CHARGING = 3.55, 3.50, 3.45, 3.30 MAX_CHARGE_CURRENT_CV_FRACTION = 0, 0.05, 0.5, 1 CELL_VOLTAGES_WHILE_DISCHARGING = 2.70, 2.80, 2.90, 3.10 MAX_DISCHARGE_CURRENT_CV_FRACTION = 0, 0.1, 0.5, 1 ; --------- Temperature limitation (affecting CCL/DCL) --------- ; Description: Maximal charge / discharge current will be in-/decreased depending on temperature ; Example: The temperature limit will be monitored to control the currents. If there are two temperature senors, ; then the worst case will be calculated and the more secure lower current will be set. ; Charge current control management referring to temperature enable (True/False). CCCM_T_ENABLE = True ; Charge current control management referring to temperature enable (True/False). DCCM_T_ENABLE = True ; Set steps to reduce battery current ; The current will be changed linear between those steps if LINEAR_LIMITATION_ENABLE is set to True TEMPERATURE_LIMITS_WHILE_CHARGING = 0, 2, 5, 10, 15, 20, 35, 40, 55 MAX_CHARGE_CURRENT_T_FRACTION = 0, 0.1, 0.2, 0.4, 0.8, 1, 1, 0.4, 0 TEMPERATURE_LIMITS_WHILE_DISCHARGING = -20, 0, 5, 10, 15, 45, 55 MAX_DISCHARGE_CURRENT_T_FRACTION = 0, 0.2, 0.3, 0.4, 1, 1, 0
 
Last edited:
DutchCookieMonster said:
My VRM

This one should work.
Click to expand...
Well, your three BMS's are currently reporting 38.8%, 38.4%, and 45% SOC, but BMV700 is 100% SOC which is your main monitor, so the LLT/JBD's aren't syncing to 100% SOC, the default config file also has limits for at low SOC, I can't remember if they're on by default, so the LLT/JBD's could be calling for lower CCL/DCL whilst actually your BMV reports 100% SOC, I guess if the BMV gets to 45-50% SOC the LLT/JBD reported SOC will be at 0% and stop discharge!

You need to sync the BMS's to 100% SOC

*edit

Looks like the BMV700 is falsely reporting 100%, you might need to adjust the BMV settings, or select a bms as battery monitor instead of the BMV, but better yet use a battery aggregator, and set the aggregator as your battery monitor.
 
Last edited:
Alarchist said:
Well, your three BMS's are currently reporting 38.8%, 38.4%, and 45% SOC, but BMV700 is 100% SOC which is your main monitor, so the LLT/JBD's aren't syncing to 100% SOC, the default config file also has limits for at low SOC, I can't remember if they're on by default, so the LLT/JBD's could be calling for lower CCL/DCL whilst actually your BMV reports 100% SOC, I guess if the BMV gets to 45-50% SOC the LLT/JBD reported SOC will be at 0% and stop discharge!

You need to sync the BMS's to 100% SOC
Click to expand...
No, the BMSs indicate the correct value. Last week something went wrong as a result of which the BMV700 (now set as a battery monitor) and the Multiplus-II incorrectly indicate 100%. I don't know exactly what went wrong. But due to renovation, we had a 3 phase 9KW heater on, and also the 3 phase heat pump, a number of small heaters and the electric stove. The system did not like this very much, with the result that the BMV700 and the Multiplus now indicate 100%. The only thing I have to do now is manually charge the batteries from the grid to 100% then everything will be the same again.
 
Alarchist said:
Well, your three BMS's are currently reporting 38.8%, 38.4%, and 45% SOC, but BMV700 is 100% SOC which is your main monitor, so the LLT/JBD's aren't syncing to 100% SOC, the default config file also has limits for at low SOC, I can't remember if they're on by default, so the LLT/JBD's could be calling for lower CCL/DCL whilst actually your BMV reports 100% SOC, I guess if the BMV gets to 45-50% SOC the LLT/JBD reported SOC will be at 0% and stop discharge!

You need to sync the BMS's to 100% SOC

*edit

Looks like the BMV700 is falsely reporting 100%, you might need to adjust the BMV settings, or select a bms as battery monitor instead of the BMV, but better yet use a battery aggregator, and set the aggregator as your battery monitor.
Click to expand...
I had used the BMV700 as a battery monitor as a test/advice victron forum. But I will put it back to the BMS.
I've had the BMV700 incorrectly indicate 100% before. But that's when a lot of energy comes from the solar panels for a short period of time.
I don't know yet what kind of settings I need to adjust for this. But first want to fix the problem with the batteries.
Otherwise, too many things will get mixed up.
 
Just an update, I haven't had the opportunity to adjust the Dynamic Cut Off yet. (due to a new floor and the tiler I can't reach the system) But as soon as I can, I will keep you informed of my findings.
 
Today I changed the DynamicCutOff in the Victron.
See the new settings below.
Now we have to wait and see if the batteries want to run out to 15%.
Minimum SOC (unless grid fails) at ESS settings set to 15%.
I'll let you know what the result is.

Code: 
TAB: GeneralSystem frequency    50Hz

Shore current    25.0    A
Overruled by remote    checked
Dynamic current limiter    unchecked
External current sensor connected (see manual)    unchecked
State of charge when Bulk finished    95.0    %
Battery capacity    840    Ah
Charge efficiency    0.95    TAB: Grid
Country / grid code standard    Europe:                EN50549-1:2019

AC input 1    Above selected gridcode plus LOM B (compliant)TAB: European grid code settings

Use Aux1 as disable FeedIn signal    checked
Maximum AC current for charge or feed in    100.0    %
Maximum generated apparant power    100.0    %
connect waiting time    60    s
connect power ramp    0.0    seconds
low frequency connect value    49.500    Hz
high frequency connect value    50.100    Hz
low voltage connect value    85.00    % Un
high voltage connect value    110.00    % Un
re-connect waiting time    60    s
re-connect power ramp    600.0    seconds
low frequency re-connect value    49.500    Hz
high frequency re-connect value    50.200    Hz
low voltage re-connect value    85.00    % Un
high voltage re-connect value    110.00    % Un
rise-in-voltage protection U>    110.00    % Un
under voltage stage 1    85.00    % Un
under voltage stage 1 delay    0.50    s
over voltage stage 1    115.00    % Un
over voltage stage 1 delay    0.50    s
under frequency stage 1    47.500    Hz
under frequency stage 1 delay    30.00    s
over frequency stage 1    52.700    Hz
over frequency stage 1 delay    30.00    s
under voltage stage 2    80.00    % Un
under voltage stage 2 delay    0.20    s
over voltage stage 2    120.00    % Un
over voltage stage 2 delay    0.20    s
under frequency stage 2    47.000    Hz
under frequency stage 2 delay    0.20    s
over frequency stage 2    53.000    Hz
over frequency stage 2 delay    0.20    s
P(f>) start frequency    50.200    Hz
P(f>) stop frequency    50.200    Hz
P(f>) start delay    0.00    s
P(f>) stop delay    30.00    s
P(f>) droop    5.00    %
P(f<) start frequency    49.800    Hz
P(f<) stop frequency    49.800    Hz
P(f<) start delay    0.00    s
P(f<) stop delay    30.00    s
P(f<) droop    5.00    %
P(U) response    Not used
Reactive power regulation    Use a fixed Cos Phi
Filter time for reactive power    3.3    s
Cos phi at point 1    1.00   
Use lock-in/out    unchecked
TAB: Inverter
PowerAssist    checked
Assist current boost factor    2.0   
Inverter output voltage    230    V
Inverter DC shut-down voltage    37.20    V
Inverter DC restart voltage    43.60    V
Low DC alarm level    43.60    V
Do not restart after short-circuit (VDE 2510-2  safety)    unchecked
enable AES    unchecked
TAB: ChargerEnable charger    checked

Weak AC input    unchecked
Stop after excessive bulk    unchecked
Lithium batteries    checked
Disable VSense (for diagnostic purposes)    unchecked
Configured for VE.Bus BMS    unchecked
Charge curve    Fixed
Absorption voltage    56.80    V
Float voltage    54.00    V
Charge current    110    A
Repeated absorption time    1.00    Hr
Repeated absorption interval    7.00    Days
Absorption time    1    Hr
Stop charger below    5.0    deg CTAB: Virtual switch
HTAB: Usage
Virtual switch usage    Do not use VS
TAB: Assistants

TAB: Assistant Configuration
ESS (Energy Storage System) (size:1761)
*)    System uses LiFePo4 with other type BMS
    (This can be either a BMS connected via CAN bus or a BMS system in which the
    batteries are protected from high/low cell voltages by external equipment.)
*)    The battery capacity of the system is 840 Ah.
*)    Sustain voltage 50.00 V.
*)    Cut off voltage for a discharge current of:
    0.005 C= 47.00 V
    0.25 C= 47.00 V
    0.7 C= 47.00 V
    2 C= 47.00 V
*)    Inverting is allowed again when voltage rises 1.20 V above cut-off(0).
*)    The solar converter will start reducing its output power at 50.20 Hz.
    Output power will be reduced to minimum when the frequency is  52.70 Hz.
    The converter will disconnect when the frequency is higher than  53.00 Hz.
*)    Total installed PV inverter power is 8000 Watts.
    Total installed PV panel power is 8000 Watts.
*)    Relevant VEConfigure settings:
      -  Battery capacity 840 Ah.
      -  PowerAssist checked
      -  Lithium batteries checked
      -  Dynamic current limiter unchecked
      -  Storage mode unchecked


Total size of all assistants including the required
(hidden) system assistants is: 1834TAB: Advanced
limit internal charger to prioritize other energy sources    unchecked
 
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