Steve_S-Tech: My Final Config for Midnite Classic SCC & JKBMS' w/ Large Bank (works amazingly well) Includes Charge Profile & BMS Config

[Steve_S]

INTRO: I have debated posting this for a while until I got everything tweaked in and working as best as possible. The End Result is Gobsmackingly Good !
I cannot speak for other SCC and such as each is different & unique in their own ways BUT this may likely be a Good Reference.
Civility & Politeness is required in this thread.

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My FINAL Tweaked out settings, NOTE this is for 24V system, Using a Midnite Classic 200 (not really designed for Lithium Based due to single decimal point accuracy. I am also posting the JKBMS Settings which by the time the packs enter Float Mode they are very nicely Balanced.
Important FYI, Active Balancing Quick Guideline is 1A Balancing per 100AH / 200AH - 2A Balancing / 300AH - 3A and so on.

Midnite Classic Charge Controller Settings (Effective since Finalized build June 2022)
All equipment MUST BE Voltage Corrected & Calibrated (VERY IMPORTANT)
Divide Values X2 for 12V. Multiply X2 for 48V.
Bulk / Absorb: 27.6V (Absorb for 45 minutes (3.45vpc) (some call this boost)
Equalize: OFF
Float 27.5V (3.437vpc)
MIn Volts: 21.2V (2.650vpc)
Max Volts: 28.6V (3.575vpc)
Rebulk Voltage: 25.6 (3.200vpc)
End Amps/TailCurrent: *1 (Triggers change from Absorb to Float)
(*1): End Amps is calculated: (100AH X 0.05 = 5A or 280AH X 0.05 = 14A.
EndAmps = TailCurrent
Coulumbic Efficiency / Battery Status Meter Efficiency for LFP = 99%.
This gets the bank charged to full with high amps (Constant Current Constant Voltage) and then float (Constant Voltage, Variable Current) tops off so the cells are at 3.437Vpc. I
! Do Not forget to adjust for Voltage Offsets between Actual Voltage @ Battery Terminal & at Solar Controller.

BMS With Active Balancing should be set to start Active Balancing at 3.420V or possibly lower to 3.410 so that the cells can balance out at the top and not affect the charging process.

Very Special NOTE: Floating & Saturating to 3.437vpc, accounts for the Voltage Settling post Charge of any kind which actually brings the cells to just below 3.400Vpc.

EDIT - July 7 2022.
Voltage Corrected & Calibrated (VERY IMPORTANT)
- Midnite Solar Classics SCC's can be programmed for OFFSETS.
- Not all are capable so to adjust values it will have to be in charging values AS WELL as your Inverter/Charger.
- Even 0.1 Volt offset Can & Will affect operations
The simplest Way
Use 2 or 3 Decimal Accurate DVOM/DMM.
While SCC is Charging, Measure the Real Voltage coming out of the SCC and write it down, Same for the Inverter/Charger @ its BATT Terminal.
When Batts are in a + Charge (NOT when Discharging) measure the Voltage @ its/their Battery Terminal Lugs.
There WILL be some variances but there is always some Line Loss between these devices, Most important is what is going into the BATT.
Check your notes from each test. That Differential in Voltage must be Compensated for !
Take that Voltage Offset and apply it to the SCC, either an Offset Function or by the Charge Settings
IE, Assume SCC to Batt Terminal is 0.1V and you are Charging, Bulk/Absorb/Float Adjust the values UP. IE If Absorbing @ 27.6V increase that to 27.7V to compensate and the other Values as well. DO NOT FORGET to do the same for Low Voltage Disconnect !
The Inverter Needs two values;
The Charging Voltage offset applied as Above You got that value in your tests above. With SCC Charging.
Low Voltage Disconnect. MUST BE Measured when No SCC Charging is happening and the inverter is drawing from BATT only. It will be different than when SCC is charging the batts. Use that to adjust for Low Volt Disconnect ! Or you may get a Late Disconnect @ Low Volts making the disconnect lower than you set. NOT A GOOD THING !

Lastly, be aware that every Fuse/Breaker, Lug & Batt terminal adds to Voltage Drop collectively due to resistance.
---- End of Edit ----

What is a WizBangJr ?

Description:

The Whiz Bang Jr is a current sense module that attaches to the standard 50mv / 500A Shunt (MNSHUNT) and wires into the Classic and KID charge controllers to give Amperage readings from the shunt. To use the Whizbang jr (MNWBjr) with any of the Classic Lites, you will either need the local app or an MNGP.

* Sadly designed for Lead Acid Chemistries and therefore only Single Decimal Point Accuracy. Similar higher Accuracy Smartshuts like Victron (2 decimal point accuracy) can also perform similar functions for various SCC's. The SmartShunts from Victron are good.

JKBMS SETTINGS (warning, long) BELOW the Main BMS status screens showing the Delta between cells in ALL Packs. 2 Shown.
ATM that is 2x174AH Used EV Grade LFP & 2x280AH ESS Grade (what many call Bulk or B grade)




THESE SETTINGS UPDATED AS OF April-9-2024
this is for a Standard JKBMS-150A (Non-Inverter Model)


















































Hope it helps, Good Luck.

 

[MrM1]

I just this past week installed my 2nd Classic 150. I do not have them in Follow me (not sure if it is necessary), but plan too maybe soon ish. But I had been searching on Monday for your original Classic Charge profiles. Thanks for the update.

 

[Steve_S]

I just this past week installed my 2nd Classic 150. I do not have them in Follow me (not sure if it is necessary), but plan too maybe soon ish. But I had been searching on Monday for your original Classic Charge profiles. Thanks for the update.

You are Most Welcome my friend... Interesting coincidental timing eh.

I gave up on anything Midnite - quit their forum too..
Entering into EndStage of my Cancer now has redirected me a LOT as the end is visible and it's no joy.

 

[toms]

Well done for comprehensively sharing your setup info. Very sorry to hear of your illness - i wish you well.

 

[Dynoman]

I have learned a lot from you on this forum over the year(s). From your documents to informative teaching posts. Thankyou. Very sorry to hear of your illness.

 

[Steve_S]

I have learned a lot from you on this forum over the year(s). From your documents to informative teaching posts. Thankyou. Very sorry to hear of your illness.

Thanks for the sympathies but I am actually really good with it, was just hoping, wishing/dreaming to get to at least my BDay next year but that's fine. I will finally be at real rest.

As for my posts, I have done a lot of documentation for "End Users" over the years on various subjects. One of the first rules is to never write at an expert level as most just are not there for myriads of reasons. So always try to explain so that anyone @ any level will understand. It is actually quite shocking how many people get offended and they do not realize that ANYONE from ANY LEVEL @ Any Time could be reading the info as presented, assume nothing, and write to a common denominator level for everyone's benefit.

I'm happy you gained knowledge from my posts!
Thanks & Have a Great Day.

 

[scpanish]

Steve,
So sorry to hear about your cancer. I didn't know.

Your posts have been valuable, and my 28KWH LFP build, delayed by months for shoulder surgery, goes online tonight. I'm not fond of the Classic or other MS stuff, voltage sense is awful on my old unit, but will keep it until the rest of the system gets updated later this year.

Wishing you the best.
the other Steve in the outback,

 

[ghostwriter66]

Steve. As all the above has said - Thank you for all the stuff that you are doing and have done. I was thrown into this job with literally knowing nothing about solar. The great part though was the ppl around me knew even less so even when i made really stupid mistakes and things caught on fire or shorted out i could just blame it on inferior "Chinese products" (which actually is a little ironic) ..

Anyway - you've helped me out tremendously over the last 2 years to the point that I am blowing up less and less things ... I do enjoy the way that you are very detailed but not to the point of losing ppl along the way in your explanation.

I am truly sorry to hear about your illness. Its a strange world we live in and miracles occur everyday ... so hopefully a little peace and perhaps a miracle comes your way ...

 

[Steve_S]

I added information (readers digest version) for Voltage Corrected & Calibrated (VERY IMPORTANT).
Hope it Helps, Good Luck

 

[MrM1]

@Steve_S wish you well sir. You've always been very helpful. Thoughts and prayers are with you.

 

[Steve_S]

Quick Update on this.
Most are aware that I was in Hospital for a while, so nothing was watched/observed or fiddled with.
Everything continued to operate @ 100% Perfect ! No logged errors on ANY BMS, SCC etc everything just hummed along ever so happily.
This is also Confirmation that my final Config is "Dialed in" and without issues. Just passing it along for the curious.

Hope it Helps, Good Luck.
Steve

 

[OffGridGuy]

Steve,

As I've mentioned before, I've had this off grid property for 20 years and I have finally switched over to Lithium based batteries, this year.

Since your system is almost exactly the same as mine (Midnight, JKBMS, Trace) I've been watching your progress with interest.

After the last update to your guide, I made some minor tweaks on my system. I was happy to see that my system is also running @100% Perfect !!!

Thank you and I'm glad to see your doing better !!!

DennisB

 

[burgerking]

Is this showing on the app? on a new app version?
Or did you edit the screenshot?

 

[Steve_S]

When you capture a Screen you can add Text to it. I ID my batteries Labels that way as well that way I know which I am looking at.

 

[Steve_S]

UPDATE regarding Entering FLOAT & Topping off Cells within the Packs. (Parallel Bank)
4 Battery Packs online, 5th (280AH) about to be recommissioned (illness screwed that up)
Shown Below:
- MIdnite Classic 200 data screen after entering Float @ 12:00 hours (time delayed as I can only be 1 place at a time.
- Both 174AH Used "Genuine EV" packs, built from the ShunBin disaster. AVOID Shunbin Vendor at ALL Costs !
- Both "hot/current" 280AH eve cell packs.
! -- Images shown full Sized (PNG)

REMEMBER: Once LFP reaches Actual 100% and Float ceases, the battery packs WILL Settle a slight bit which is perfectly normal for this chemistry.

Classic Screen. (NB Battery Efficiency is set to 99% and IS ACCURATE ! - Verified.)

NOTES:
- Current Configuration IS 908AH & will increase back to 1190AH when Pack 5 (280AH) is back online.
- Net Ah: @ 0AH because of the trickling (Variable Current from Float) topping off to a total of 100% within the
Working Voltage Range. (3.000-3.400)
-- This will increase to 1AH once completely at 100% on ALL Packs.
- SOC already registers as 100% due to the "finishing"
- Voltage Push with a -0.2V Offset is 27.5V (27.3 Actual) this varies a LITTLE as toping up and reduces will arrive at 27.3V per pack.

The Pair of 174's.


The Pair of 280's.


NOTES:
The system just entered FLOAT Mode approximately 5 minutes previous.
Float is trickling in as needed and Topping of ALL Batteries to 100% Equalized & Balanced and will be complete in under 1 Hour !
Float is also providing the Inverter with ALL that it needs to operate the home without affecting Battery Charge Process.
The Time Stamps are shown on the Capture Screens.
There IS a wee bit of variance at this stage due to Pack Sizing, this is expected & normal.
There are NO ERRORS in ANY LOGS AT ALL ! and not for at least 2 weeks now.

I hope this answers even more Questions and resolves a bunch of other Twaddle going on in the forum.
Steve.
.

 

[12kw_2021]

Steve ... I have a Sol-ark 15k inverter just up and running with a JK BMS and 16 280Ah EVE cells connected. Are the parameters you have in the first post above recommended for input to the screens on the Sol-ark that have some reference to Float and Absorb and equalize? Are these setting you recommend good for EVE batteries or generic for any Lifep04 battery. Thanks in advance for educating me on this stuff.

 

[Steve_S]

Thesze settings would be fine for you (doubled for 48V of course).
Never Ever equalize any Lithium based cells that is for Lead.
This is fine for ALL LFP/LiFePo4.

 

[12kw_2021]

Thanks you very much.. I will make use of them in my Sol-ark Setup screens.
God bless and hold you. (No offense intended)

 

[x98myers7]

sure could use some help on my Midnite config. bulk and absorb seem to work fine. when I hit float under load, it fails to actually bring it up to appropriate float voltage. as soon as it hits absorb limit and into float, bank immediately goes to 26.8 and drops as if the Midnite is not even charging. clearly the Midnite is not seeing the load.

what's config'd wrong?

 

[Steve_S]

Depends on the load.
A load will always cause some voltage sag, bigger sag with bigger load. Once the load is removed, float should increase to its setting (provided there is enough solar to supply it). It is capable of pushing Amps bank into the batteries If there is enough input to do it.
IF a load is more than Float can supply on its own from solar input, the inverter will draw the balance of what is required.

There is also a setting in the SCC for "offsets" in the advanced config section. From the LCD panel, it is under TWEAKS. Check your SCC's voltage output with a DMM, then check the voltage @ your battery terminals, there will be an offset (difference). Use the Up/Dn arrows to raise/lower the offset to match what is seen at the battery. NOTE there is also an offset setting for DC In from the panels, be careful not to mix them up LOL.

Hope it helps