Author Topic: New Lithium Setup  (Read 399 times)

plongson

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New Lithium Setup
« on: August 07, 2021, 09:47:25 AM »
Greetings! I'm a longtime member that has not been around for a while!!

Just some background...

We've been off-grid for 10 years and our Rolls-Surrette FLA's finally bit the big one, after a slow decline...and are being replaced with a 18.5 kW lithium battery. It won't arrive for 6 weeks so I have time to get things ready. About three years ago, we pulled in city power but just used it for AC in the hot times, pumping water and conditioning the FLA's when needed...Power bill was about $30/month...with the current state of energy production in the USA, low water (drought)/no hydro, coal fired and nuke power hated by nearly all, I can see a time when grid power might not be available, but... enough of that.

We use a Magnum 4448PAE inverter and a Midnite Classic 250 with about 2350w of solar...now it's all about getting the settings correct for the new battery. Magnum publishes recommended settings for their inverter and lithium but I'm not sure where to set my Classic 250 AND should I install a WizBang Jr.

Can you guys give me a hand? I'd like to start a dialog so I'm sure I can get long life from this HUGE (for us!) investment.

THANKS!! In advance for any and all tips and information!

Paul
« Last Edit: August 07, 2021, 09:49:38 AM by plongson »
10-Astronergy 235 watt panels
Fixed 180° south face-No tracker
Midnite Solar Classic MPPT Charge Controller 250V
Mini-Magnum MS4448PAE Power Center
Battery Bank: Fortress E-Vault MAX 18.5kW Lithium
Kubota SQ1200 21kW diesel genset
Lat/Long 37.8 N 113.1 W

KyleM

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Re: New Lithium Setup
« Reply #1 on: August 07, 2021, 02:27:46 PM »
This would be a good place to start:
http://www.midniteftp.com/support/kb/faq.php?id=75

-Kyle

plongson

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Re: New Lithium Setup
« Reply #2 on: August 07, 2021, 03:10:44 PM »
Thanks for that link! But there is an interesting paragraph...

NOTE: It is actually the BMS that is charging the battery. The Classic can not be setup to insure EACH Cell gets a proper charge. Over-charging a Lithium Cell can have disastrous results as well as financial consequences.

If this is the case (forgive my ignorance) why is there even a need for an additional charge controller if the BMS is in full control of the charge??
10-Astronergy 235 watt panels
Fixed 180° south face-No tracker
Midnite Solar Classic MPPT Charge Controller 250V
Mini-Magnum MS4448PAE Power Center
Battery Bank: Fortress E-Vault MAX 18.5kW Lithium
Kubota SQ1200 21kW diesel genset
Lat/Long 37.8 N 113.1 W

ClassicCrazy

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Re: New Lithium Setup
« Reply #3 on: August 07, 2021, 05:37:12 PM »
Thanks for that link! But there is an interesting paragraph...

NOTE: It is actually the BMS that is charging the battery. The Classic can not be setup to insure EACH Cell gets a proper charge. Over-charging a Lithium Cell can have disastrous results as well as financial consequences.

If this is the case (forgive my ignorance) why is there even a need for an additional charge controller if the BMS is in full control of the charge??

The Classic provides the  charging current -    the BMS is usually designed to protect the battery from over voltage, under voltage, over current draw, and making sure each cell is balanced with each other.
You will have to find out what exactly your particular BMS is designed to do and  it's specs. 
There are some other recent discussions on forums here about lithium batteries which would be good for you  to read since they have lots of details.

Larry
« Last Edit: August 07, 2021, 05:39:52 PM by ClassicCrazy »
system one
Classic 150 , 5s4p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system two
Classic 150 ,5s 135 watt Kyocero , 16s Calb 100AH LiFePO4 , Outback VFX 3648 inverter
system three
Midnite KID MPPT 24 DC in to  12 volt AGM batterie

plongson

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Re: New Lithium Setup
« Reply #4 on: August 08, 2021, 08:40:06 AM »
Thanks Larry, Do you think the WizBang is something that is essential to the care and feeding of a lithium? Will the Classic look at the data provided by the WBJ and adjust how it charges, or is it more for the operator of the system to monitor status?
10-Astronergy 235 watt panels
Fixed 180° south face-No tracker
Midnite Solar Classic MPPT Charge Controller 250V
Mini-Magnum MS4448PAE Power Center
Battery Bank: Fortress E-Vault MAX 18.5kW Lithium
Kubota SQ1200 21kW diesel genset
Lat/Long 37.8 N 113.1 W

ClassicCrazy

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Re: New Lithium Setup
« Reply #5 on: August 08, 2021, 10:45:00 AM »
Thanks Larry, Do you think the WizBang is something that is essential to the care and feeding of a lithium? Will the Classic look at the data provided by the WBJ and adjust how it charges, or is it more for the operator of the system to monitor status?

The Whizbang is only active in charging if you use it for setting up Ending Amps . I believe Ending Amps is used by some people with lithium batteries. Even if it wasn't used the Whizbang is a must have in my opinion for the data it gives on exactly how much current is going into batteries and what is going into loads.

Larry
system one
Classic 150 , 5s4p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system two
Classic 150 ,5s 135 watt Kyocero , 16s Calb 100AH LiFePO4 , Outback VFX 3648 inverter
system three
Midnite KID MPPT 24 DC in to  12 volt AGM batterie

plongson

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Re: New Lithium Setup
« Reply #6 on: August 08, 2021, 12:36:47 PM »
Gotcha...I'll seriously look into adding it to the Magnum 4448PAE.
10-Astronergy 235 watt panels
Fixed 180° south face-No tracker
Midnite Solar Classic MPPT Charge Controller 250V
Mini-Magnum MS4448PAE Power Center
Battery Bank: Fortress E-Vault MAX 18.5kW Lithium
Kubota SQ1200 21kW diesel genset
Lat/Long 37.8 N 113.1 W

Bob D

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Re: New Lithium Setup
« Reply #7 on: August 10, 2021, 06:01:57 PM »
A lot of the system design depends on the specific BMS.
Some just monitor the hi-hi and lo-lo cell voltages and cut things off to prevent battery damage.  They also generally provide some degree of cell to cell balancing.
In this case the charge controller is a bit more actively involved, and people discuss bulk-absorb-float voltages at great length.

Other BMS's monitor the hi-hi and lo-lo for battery protection, and also monitor hi and lo cell voltages to stop the charging and discharging.
In this case the system needs to be capable of terminating charging upon getting the signal from the BMS.

In my case, the BMS sends a signal to the Classic 150 to stop charging. An input into AUX2 forces the Classic to rest.  WHen the battery drops a bit (in my case either to a settable SOC or a settable voltage, charging resumes.  The Classic is set to 29 volts ( absorb) and it only ever runs in bulk mode of resting. So it is just doing the MPPT interface with the panels.  Similarly, the BMS will send a signal to the inverter disconnect (like the low voltage cutoff in the inverter) and will restart at a settable voltage. I also have a Magnum inverter (MS4024) and use their RSA adapter to connect to the BMS (btw the adapter is just a RJ12 phone cable).  One could just use the inverters internal disconnect but that doesn't measure individual cells, which is critical with LFP.
The hi-hi and lo-lo trips, which would only occur if the charging or discharging normal signal failed, trip a set of shunt trip breakers on the inverter, the PV in, the Classic out, and the generator.
The AUX2 connection required that I disconnect the WBJr, but the BMS has an accurate SOC indicator.

Anyway, you need to look at the BMS and its cap[abilities, and check with the battery supplier .
Classic 150, Magnum 4024, 12-215W panels, 12-85-13 forktruck battery

Steve_S

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Re: New Lithium Setup
« Reply #8 on: August 11, 2021, 04:17:13 PM »
I would like to add a few points.
A BMS has the function of protecting the cells and complete battery assembly.  This covers both High or Low Voltage cutoffs, at both the Cell & Battery pack level and High or Low Temperature cutoffs points.

Some BMS' have additional capabilities such as Passive or Active Balancing, Communications interfaces like CanBus, ModBus, RS232/485 to interact with various types of gear like Solar Charge Controllers & Inverter/Charger Systems.  SmartBMS' are also available which allow for a Phone APP or Computer interface to program, monitor & control the BMS system.

Typically, Lower Amp Hour Capable systems use FET Based systems, while systems that are used at higher amperage rates use Relays of SolidState Contactors.  This threshold is 200A & above as an unwritten rule.

Please provide a Link to the battery system you've purchased and hopefully the doc link as well.  This can further assist in how to interface with the pack.

------------------------------------
Battery System note.
A GOTCHA With Lithium Base Battery systems !


FLA is essentially a "Brute Force" battery compared to Lithium, even LFP batteries. 
Appreciate that with LFP the "Working Voltage" per cell is 3.000-3.400 Volts per cell.  YEAH, 400 millivolts for 100's of Amp Hours of stored energy.  The Gross  Voltage range is from 2.500-3.650 Volts per cell.  Premium Grade A++ LFP cells working range is typically 2.900-3.450Vpc.  It is very important to correct/compensate for the voltage readings between your battery system & your SCC/Inverter/Charger.



When using one single battery pack, like can be quite simple /s ;-) .  Low Volt & Hi Volt disconnects can be set on the SCC & Inverter/Chargers.  With the Classic, using the WizbangJr with End Amps (Calculates as 200AH X 0.05=10A) plus float LFP can be kept quite happy.  With a single pack, interacting with the Classic or Inverter is not hard either.

Multiple Battery Packs in Parallel becomes quite another issue when it comes to interacting with the other equipment.  It isn't hard but takes planning & consideration and depending on the level of interaction it can get quite in-depth.

-----

I myself transitioned from 8-Rolls S550s 24V/428AH Gross to 1190AH (30.4kWh) of LFP in 5 parallel packs.  3x24V/280AH & 2x24V/175AH.  The FLA Bank is now a secondary bank.   DANG IT, can't link the diagram.... grumble.

Here is my Classic-200 LFP Profile for your interest.
Divide Values X2 for 12V. Multiply X2 for 48V.
Absorb: 28.2 for 15 minutes (3.525vpc) (some call this boost)
Equalize: OFF
Float 27.9V (3.4875vpc)
MIn Volts: 22.0 (2.750vpc)
Max Volts: 28.7 (3.5875vpc)
Rebulk Voltage: 27.7 (3.4625vpc)
End Amps: 14A (*1)

(*1): End Amps is calculated from the Highest AH Battery Pack in a Bank. IE: 200AH X 0.05 = 10A 280AH X 0.05 = 14A.
NB: Victron Forum discussion says EndAmps = TailCurrent
This get's the bank charged to full with high amps (Constant Current) and then float (Constant Voltage) tops off so the cells are on average between 3.475-3.500. I am running 7/24/365 so float is used up by the Inverter + provides whatever the packs will take to top off.
** Coulumbic Efficiency for LFP is 99%


Hope it helps, Good Luck.

Classic-200, Samlex EVO-4024 Inverter/Charger, 1190AH/30kWh of LiFePO4 & 856Ah of Rolls Surette LEAD.

mahendra

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Re: New Lithium Setup
« Reply #9 on: August 11, 2021, 10:45:25 PM »
Thanks Larry, Do you think the WizBang is something that is essential to the care and feeding of a lithium? Will the Classic look at the data provided by the WBJ and adjust how it charges, or is it more for the operator of the system to monitor status?

The Whizbang is only active in charging if you use it for setting up Ending Amps . I believe Ending Amps is used by some people with lithium batteries. Even if it wasn't used the Whizbang is a must have in my opinion for the data it gives on exactly how much current is going into batteries and what is going into loads.

Larry
Yes I have always said it would be great if midnite could have done a wb Sr.to cater.for lithium batteries it already has a lot of features required .only thing that's missing is cell individuality.
1.5kw on Midnite classic 150(whizbang jr.) networked 0.660kw on classic lite 200 ,180ah CALB Lifepo4 48v battery bank,123SmartBMS bms(top balanced) Outback vfx3648