Hello everyone,
I recently installed a MultiPlus-II 48/3000/35-32 with a 4,2 kWh lithium battery. How can I set a maximum SOC limit (eg. 90%) with ESS Optimized without BatteryLife selected?
Thanks in advance!
It’s not possible to set a max. SOC. But you can set CVL to a lower voltage or lower CCL. You can do this via Node-RED.
if you’re using a schedule then it’s possible
May I ask why you would want to do that?
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You can use node-red, here is a flow to set DVCC to 70 or 0 based on SOC. If its below 90 set it to 70 and above set it to 0. This will disable the internal charger. If you have DC solar and you don’t want to charge to 100% you can export with an algorithm to set the grid setpoint or disable the charge controller. You really can do whatever you want and can imagine. Hope this helps. I have pasted the flow adjust as required.
Added flow to text document below.
The idea is to maximize battery life by charging everyday to 90% (or set a equivalent charge voltage limit), and once a month do a full charge to let the BMS balance the cells.
I see, many thanks.
right here man you can go into ESS → schedule and set daily or weekdays to 90%, this is midnight to 6am example, then make a 2nd schedule once a month same thing but make it 100%
you can make up to 5 schedules using the cerbo GUI in ESS menu
I’d like to test this solution but when I copy/paste into node-red it gives me an error. Any tips for getting it to work? Do I need to add some libraries to node-red?
Thanks in advance
It might be something to do with pasting it in here. I have saved it to a text file see if you can import this.
MAX SOC NODE RED.txt (5.9 KB)
Sadly it is not possible to limit upper SOC limit, this is a capability we URGENTLY need, as it would dramatically increase battery life. It is hard to understand why Victron would not put such an obviously helpful and useful option in.
@Victron … please fix this, it is ridiculous that we do not have an option to limit upper SOC.
For those who might ask the question why… Lithium based batteries die much faster if charged to 100%, if you avoid charging them to 100% you can double to triple their lifetime. And to make it clear, that is valid for Lithium iron based cells as well, not only NMC! The only reason why there are some suggestions (like from Tesla with their lithium iron phosphate models) to charge to 100% once a week… the reason for this is the very flat voltage curve of lithium iron vs. NMC cells, and for an EV you absolutely need to have a pretty precise evaluation of SOC/range, therefore you need to recalibrate the range calculation, and the sharp voltage drop at low SOC and high SOC is the only way you can do that, while NMC cells have a much steeper voltage curve making such a calculation much easier.
But for extending lifetime… it is absolutely essential to avoid charging to 100% when not absolutely necessary. If you want to read into this, look up recent battery studies and watch for DOD (“depth of discharge”) and watch the dramatic differences in cycly lifetime between high and low DOD charge cycles.
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You can try this one as well and disable the solar charge controller and internal charge controllers with these flows.
DISABLE CHARGER BASED ON SOC.txt (9.9 KB)
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It appears to be working but since it’s been cloudy in the last couple of days I haven’t actually see it stopping at 90% SOC. I’ll report back when it does 
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