Idea

The challenge you have here is the battery vendors don't want their products used this way and I doubt victron would want to start mucking with parameters which could affect that warranty and potentially cause them support issues related to imbalance and SOC drift, as examples.

On a similar topic, I previously shared a SOC histogram for an ESS, it clearly showed that the battery didn't spend enough time in the "undesired" area. For me, at least, this seems to be a non-issue.

Why should this limit any warranty? It is up to me as user to decide which SOC range I will use and I am interessted to be in the best operating range as much as possible. Charging every day to 100% makes vendor happy because the can sell a new battery very soon.

If you are using Louis VanDer Walt's BMS interface code, this can be done as the Max cell voltage and Max Soc state interface to the d-bus charging commands are accessible. I configured my set-points on the maximum cell voltage (and Min cell voltage) as these are the most critical values for cell life. Max voltage was backed off 100 - 150mV from manufacturer's specified limit, min was raised similarly. Battery max charge current is also ramped down as max cell voltage is approached - this eliminates any overshoot in larger systems with slow response times. Time spent near max is usually limited to 4 hours per day, so this is not a major issue.

Hi Baxter,
I fully see your point and agree with your requirement. I covered almost the identical requirement in this thread.

In addition to the fixed Min-SOC I implemented a forecast dependent dynamic Min-SOC approach preventing a long term discarge.

The max-SOC feature (inclusive periodic balancing) is currently in beta test, however it showed quite good results recent weeks so far.

Here is another practical example why regularily loading the battery beyond 80% SOC cannot be valuable to battery life. Mentionable is the peak increase after 80% by additional ~10°C. That can't be healthy to battery chemics.

My main problem beside the need to reduce the max SOC in summer is, that i use CANBUS based BMS, which overwrite the DVCC max. Voltage setting. I would be fine with a max. voltage setting as well, but anyway anyhow, it doesnt work for me, or did i get something wrong!?

--> on the other hand, i understand that voltage related max. soc setting for lifepo doesnt work (but i use nmc)

--> if you use good BMS's which calibrate at LOW and HIGH voltage, even use other algorithm, the SOC can be very accurate, as it is when you use for example REC-BMS, as i do. I am very satisfied with the accurateness of the SOC

@Baxter:Have you found a solution to the problem (SOC - DVCC)?

I have the same "problem" and I want to stop all loading loading devices (MPPT, Quattro, etc) when SOC is higher than 90%.

But at the moment I only see the possibility to use the Generator on/off Relais in the GX to manually stop the Chargers...not really user friendly.

Set a slightly lower charge voltage limit for managed batteries in dvcc..

If you are "handy" at programming, you can modify the python script that is responsible with the whole DVCC stuff and set there the battery limits when your particular needs regarding SOC are meet.

The script is found on: /opt/victronenergy/dbus-systemcalc-py/delegates/dvcc.py

A function where you can implement this is: _adjust_battery_operational_limits(..)