Is there by any chance somewhere a list with all optimum values for a JK Inverter BMS with EVE MB31 LiFePO4 grade A cells.
The values appear to change from time to time on the Internet. Even for Andy’s off-grid-garage settings. Mad that you have to search high and low just to get good values.
Different settings depend on different user requirements. Do you want more security? Do you want to utilize your battery capacity as fully as possible? Or do you want to maximize your battery life?
The joys of a self build, DIY and learning.
All relevant. The EVE cells have a datasheet that should have some information as well. Usually the voltages are tailored for the cells used and the questions tomberger asked.
Hi Tom. Good question. For me safety is key. I guess also a requirement for the insurance company. Just to be on the safe side of things. There’s no need for me to stress the battery bank. I rather add one. That is if required. Time will tell of course.
True Absolutely. I love learning new stuff, but also know my limits. Some people are cocky about their absorbed know how, but then something bad might happen. Like a back-wall of some building blowing off to eternity,
True you don’t know what you don’t know and i don’t either. And the problems with bad lithium set ups dont show immediately, (unless there was a catastrophic error) it is usually 2 or 3 yeas of use where the damage is noticed.
It certainly does not help that there is a lot of stong opinions mixed with fact and fiction.
So many different methods for balancing and ideas behind it.
The easiest way is to look at cell datasheets. Use the cells in the flat part of the curve. Maybe with a small overshoot on the top end of the curve for making sure it is full and balancing purposes and to keep absorption short.
Setting them up properly from the beginning like balancing the cells from the start.
Just like me. That’s why I only discharge the battery to a minimum of 20% SOC in the summer and only to 50% in the winter. And I charge to a maximum of 3.45 V per cell, just enough to allow for balancing.
Like I said. I don’t like to stress the prismatic cells. Not even the brand new grade A cells. And thus set the voltage to 3.45 and that is enough for me. I think that I use 3.350 as float voltage. Can’t really recall the used absorption voltage, but that should not be too far of it.
By the way. I noticed that the JK Inverter BMS reports a lower voltage. The SmartShunt is 0.8 volt higher than the BMS. SmartShunt is correct. Verified with my Fluke. No idea why JK BMS is this far off. I mean the Victron SmartShunt is connected to the BMS output, and goes to the MP inverter.
Voltage on the inverter is also spot on. I verified the voltage between bat-min and bat plus. Same voltage. JK is wrong.
Yes all the ones i have ever set up are like this.
If you dig in the settings there is a voltage calibration box. You can change it there.
Excellent. Nice to hear you are a thorough person. I can’t believe how many people throw a system together without checking anything.
Charge settings are specific to the battery (and vendor) not the BMS. I would use the same settings for my battery bank without regard to if I was using a JK or JBD BMS.
If you’re willing to read through a lengthy thread, this is a good read:
Thanks. I found the setting earlier and was wondering what it did. Zero amps current now and it is spot on. Thanks 
After calibration (in the JK Inverter BMS settings) the voltage is reported accurate.
But the JK inverter BMS has severe problems with SOC calculation. Until the last firmware update the SOC was reported much too high: after a week or so of not reaching 100% SOC I noticed that it reported 50% SOC but a (accurate) voltage of only 49.x V (which means less than 20% SOC). With the newest firmware the SOC tends to be calculated too low, and JK obviously achieved that with a really dirty trick: at charging the BMS reports a almost perfect current value, but when discharging the reported current is much, much too high. Obviously the new firmware simply multiplies a factor to discharge currents to get a more precise SOC. I have seen the BMS reporting a discharge current of 18 A, while the real discharge current was only 12 A.
Hi Jim. Of course. I get that. The thing is that the used text for the settings is. Well at least sometimes, a bit of a question mark. Not every vendor is using the same kind of text. Please note that this is my first ever JK BMS. After having used Daly BMS before.
Thank you for the link. You know what. I’ve followed Will from his younger years, whilst living in his RV. Great chap. Great info and always a pleasure to read the forum posts. Let me go check your link. Thanks 
Great. I’ve ran into data that was wrong before. Like their fish is THIS BIG…and you end up with a tiny gold fish 
What else is new 
Edit: Thank you guys. Happy Holidays!
Follow eve setting’s and cells should last at least 3k cycles and maybe more depending on which spec sheet you look at. This equates to 8.2yrs if you discharge to 2.5v / charge to 3.65v daily.
As long as eves specification is adhered to ,personally i’d be more concerned on what the cells are being exposed to physically - compression / vibration / temperature.
My jkbms has ovp @3.55v / uvp @ 2.85v, set as any lower or higher gives little % gain as well into charge / discharge knee.
Set bms and see how it goes, just keep within manufacturers specs.
Ps dont forget to check / alter as required config.ini file. If in doute great tutorial on github mr- manual.
Note i have v1 jkbms and not inverter type
The voltage or current value is measured in digital systems (not analog) that operate discretely, not continuously and as such the values are collected at time intervals, and the smart shunt and the BMS have their own time points at which they make measurements. This leads to measurement differences between the two systems. This may be one of the reasons why the values are so different especially around very short and sharp peaks. Decalibration remains the main cause especially when the SOC evolves differently on these two components.
I’ve been using prismatic cells for at least over six years now and all people say, basically, is to look at the datasheet. But like you, and others, have learned is that there is no need to follow the specs for high and low voltages.
No real gain.
I have seen a Cerbo GX that was stuck. Dead fish in the water, and that due to an apparent log file overrun. So this nice piece of Victron kit ended up doing nothing anymore. Guess what. Battery was discharged way beyond its limits. Seen a pensioner with tears in his eyes. How can two items fail at the same time? It was a costly replacement and it opened my eyes. Better safe than sorry. Extra monitoring protection installed. But will that be enough🤷♂️
