Thanks!
So the most notable one is the float voltage.
Which is best in your case for an UPS like situation, but if the battery is cycled daily and is not spending too much time in float (a solar installation), his value, if it’s set as the 100% SOC voltage, it’s OK, IMHO…
But nevertheless, this is debatable, as everywhere in the web, and the above is my opinion and may be far removed from the truth… 
You can’t keep the elements under RCV voltage all the time.
This will significantly shorten their lifespan.
It is better to undercharge this elements chemistry.
UPD: My batteries are in a cycle, every day.
Sorry, English is not my native language…
“Under” as “below”, or under as “at”. I suppose you wanted to say the later.
At least one major battery manufacturer is saying that there is no problem in keeping indefinitively the cells at the CVL.
By the way, the jkbms is computing the CVL based on RCV, or has a different set value?
I keep asking, because I have a certain particular case here and trying to understand better by picking the collective brain.
I carefully study the specifications for various elements and also track the operating experience of other people, comparing it with my own experience and measurements. My practice shows that my approach is justified.
UPD:
Mine too, It’s not a problem 
“Under” as “at”
The JK doesn’t calculate the CVL/RCV voltage, it follows the set values taking into set the calibration that can be entered manually. After requesting the set value from the charger, the Victron is able to maintain the actual charging voltage, taking into account the compensation of losses up to 1V.
UPD2: Therefore, when you have yourself assembled the battery, you need to measure the total voltage on the chain of cells & make set value calibration voltage in BMS settings. Not on the battery terminals.
There are no fundamental remarks, except for early balancing.
Don’t start it too early, otherwise it can cause imbalance and longer balancing time in absorption mode. My battery finishes balancing after bulk mode through 15-20 minutes with deviation 0.002V.
RCV Time 5 Hour its to much, 1 hour is enough.
RCV Time = It’s timer absorption voltage.
JK Algorithm
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YW
Next step measurements & calculations of values for ESS config.
You can do it!
I have seen that flowchart before, but as a programmer. And for many years. That flowchart makes no sense to me.
I know what the Runtime Charge/Float Voltage timers are supposed to do, but without any additional logic, it won’t get to point 4 before the time set for point 3 (basically a delay) is up. It would mean that it sits there. Waiting for N hours.
Now. We use an induction cooktop at home (and in the cabin) and at summer time, the battery is full when we start to prepare our dinner. The cooktop draws 7.2kW max and that means that the battery needs to be topped up again. And this charge won’t be done by MPPT chargers.
Now. What I see is that while those timers are set, is will stop charging long before the time is up. How does that work with that flowchart?
Note that there is no Over Voltage Protection triggered or anything, so what is making it stop charging? It’s not anything Victron controls, but it (read: the JKBMS) just stops charging.
To me. If this charging flowchart was correct, then I would have swollen battery cells, or at least trigger an OVP every single day. Which again is not happening here.
Feel free to test this yourself, and let me know what you think
At a current of 53A the voltage is 51.92V when the current is reduced to 6A the voltage is 52.42 volt measured by the bms.
So for 100A it would be around 1 volt of drop I think when exterpolating, but I will measure it later.
I will measure voltage and current at idle and full power with a multimeter tomorrow.
But at 0.33c the voltagedrop is already 1 volt for dynamic cuttoff according to this first measurement.
Such a voltage drop under load probably indicates an insufficient cable cross-section.
6 m already need to use 2X70mm2. This is not battery loss, most likely (99%) cable resistance under load. I design all my installations up to 3-4 m cable length on 2 poles.
UPD: Drop 1 volt at load of 0.33C is a lot.
What was the SOC under this load?
The total length is 6 meters (3 meters black, 3 meters red). With 70mm2 the voltage drop would be 0,16 volts with a loss of 16 watts at 100A which is about 0,3%, still acceptable for me.
The voltage was measured by the jkbms so no cable loss in this measurement but the voltage measured by the victron was almost the same.
I will use a multimeter to measure again in the following days.
Soc was 42%.
I don’t think you can take from battery more than 4 kW (78-80 A), because it’s limited by the maximum power of the inverter. So before you think about replacing the cable. Measure the real maximum load values at different SOC levels of the battery. Don’t rush.
I’ll do that, thank you for your support.
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Measure voltage loss at 75-80A load and SOC: 100%, 50%, 30%
And this will reflect reality.
Good morning Jeroen. It may not just be the wiring. Sometimes it also involve the on/off switch or breaker. Or the fuse.
May I make a suggestion for wiring and stuff:
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Okay, my measurements at 25% soc between 0 and 88 amps.
Voltagedrop on multiplus battery terminals: 1 volt
Voltagedrop between multiplus battery terminals and cells: 300mV (this includes cables, fuse, bms and dc switch)
Voltagedrop over all cells: 700mV
Voltagedrop over 1 cell: 50mV
According to chatgpt the voltage drop on de cell is probably due to the low soc (cell resistance is 0,497mOhm).
I will do a measurement at 100% soc this afternoon or tomorrow.
The internal resistance of the EVE MB31 cells is at most 0,23 milliohm according to EVE but at an ac voltage of 1kHz. When using dc the internal resistance can be between 0,6 and 1 milliohm 53-88 millivolt per cell at 88 amps according to chatgpt so that fits my measurements.
What is the cross-section of the cable between the battery terminals, BMS and cells?
UPD: Did you take measurements after assembling your battery?
What is the internal resistance of the battery?
50mm2, internal resistance that I measured using R=U/I is 0,56 milliohms.
The battery was already assembled during the measurements.
But the voltage drop over a cell is +/- 50 millivolts (my multimeter shows in 10 millivolt steps)
50×16 = 800 millivolts
800 millivolts + 300 millivolts for cabling, BMS, fuse and switch makes 1.1 volt.
The loss is 88 watts, which is 1.75% from 3576 watts, which sounds reasonable to me.
.
OK, Waiting for measurement results for SOC 100% and 50%