restart sbms0 vs. settings changes

[Bernd]

today I´ve changed the dmppt MAX SOC from 99% to 98% Now, the status is stil 20480 and CFET should on ON, but no charging is active.

With the 99% setting, it toogled every 10 minutes charging ON and OFF. Now with 98% setting it is OFF for more then an hour. 

It seems, I´ve missed to reboot the sbms0 to get this setting active or I´m missing something...

Does the MAX SOC setting require a reboot of the SBMS0?

I believe it would be great to have an overview, which settings require a reboot, which settings need to be set after every reboot (hopefully only date & time) and which, does not require a reboot.

e.g. EXTIOTYPE changes seem to work instantly.

Another question came to my mind:

Why is there no software option to reboot the SBMS0? The cable ON and OFF thing is not optimal as there are many cables and any cable connection issue is not what we want.

Would like to add these information to my knowledgebase :-)

[Dacian Todea]

No you do not need a reset and all is likely working correctly.

If with 99% it took 10 minutes for the charging to start it means you have no load or almost no load.

With SOC set at 98% the charging will only start when the SOC drops below 95% then when charging starts it will stop at 98% and so cycle with a 3% hysteresis between 95% and 98% for the rest of the day. 
No setting require reboot except for the settings made in Parameter settings (those related to battery) as those are stored in the ISL94203 and that is the one that require reboot. And you will only make settings in Parameter settings once when you install the battery and never after that. So you should not require any other reboot in the next 10 years.

[Bernd]

yes, my load is somewhere at 35W with a 150Ah 24V battery. Will wait for tomorrow daylight and see what happens...

so if we set it to 99% it will toggle between 99% and 100% after the first charge of the day.

If we set it to 98% it will toggle between 94% and 98%.

If we set it to 70%, would it then toogle between 66% and 71%?

Not sure, what makes sense the most, but what is the best setting for a LiFePo system?

Any degregation expected depending on these settings?

[Dacian Todea]

At 99% the SOC plays no role it just stops charging at 3.55V and starts charging when all cells below 3.4V but with SOC set at 98% or below it will use the SOC for charging and keep the SOC between the set limit with 3% hysteresis.

Yes as soon as it drops to 94% it will start charging and stop as soon as it gets to 98%

With 70% settings it will start charging as soon as SOC drops to 66% and stops at 70%

It depends on your requirements and any setting will be fine. My SBMS is set at 90% in summer and 95% in winter but there is not much of a difference. Days are shorter in winter so I want that 5% extra but is fine even without that.

As your battery is about 3600Wh and your load is just 35W that load needs to stay there for one hour to drop the SOC by 1% that means if you change the SOC to 70% it will sure not charge more than just once a day to 100% then since it never gets to 70% in 24h it will only start changing again the next day.

Even with 98% setting it may only charge two or max 3 times a day if you charge with solar as it needs 3h to drop 3% SOC with that 35W load.