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Sunny Island / Chargery issue?

Ai4px

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Feb 20, 2021
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I’m using chargery coupled to their DCC, and noticed something the other day... when charging the battery from a morning star charge controller, I noted that the charge side of the DCC was shutting off. Battery voltage was about 3.23v per cell and no cell was anywhere near 3.6 yet the BMS was commanding the DCC to stop charging. I watched the chargery display 30amps charge current, then 0 for a few seconds, then start charging again. I verified the behavior with an amp clamp meter. I’m typing this from memory, but I have not changed the high voltage cut off on the BMS from it’s 3.65v setting.

The battery is 16s of 280ah LFP cells. I think the bus bars they sent with the cells are MUCH too small, 15mm x 1.2mm, and have some 4mm copper on the way... but not here yet.

So I kinda blew off this BMS charge stopping behavior and went forward with using my sunny islands to run the house.

I experienced a problem twice today. My pair of 6048 sunny islands glitched with an error message of voltage of battery exceeded followed by the inverters shouting down their 240v output For about 5 seconds. Now I know that the DCC shutdown power TO the inverters they would NOT auto restart... instead they shut down outut for 5 seconds and restart. Makes me think that the sunny island charger was pushing some amps into the battery when teh DCC shut off teh charge direction and that caused an inductive spike on the sunny island side.

So what do you guys think? Is the DCC shutting off charging direction causing my issue? This happens randomly and Its impossible for me to run to the basement before everything resets. The only record I have is the fault log in the sunny islands.
 
The most common thing to cause that is if the cells are somewhat imbalance and exceed the difference of cell voltage setting .... are both temperature sensors connected?
 
The most common thing to cause that is if the cells are somewhat imbalance and exceed the difference of cell voltage setting .... are both temperature sensors connected?
Yes indeed both temperature sensors are connected To the BMS. I did not top charge to 3.7v, but simply connected all in parallel and let them settle in... they were all at 3.3’ish from factory.... now when charging I do see chargery jumping around randomly telling me a different cell is the high one. The greatest diff between hi/lo cells I’ve seen is like 70mv on the chargery display.
 
What version of the software do you have?

There were some changes in the recent updates that improve that bouncing cell voltage thing ..... The 4.02 manual also explains how to use external power instead of power thru the cell leads .... that helps that problem and improves accuracy also.
 
In the BMS Config there are setting for Over charge Current. Have you adjusted those beyond the default ? which is defaulted to 40A I believe.
With 280AH cells they can take up to 140A / 0.5C-Rate.
Also make sure you are running the most current firmware http://chargery.com/update.asp

The 2mm x15mm busbars will handle what you have going on. You made no comment about what the BMS sees for IR on the cells, that is a good indicator of things. It takes a while to get a reading as the cells have to charge/discharge a bit for it to show properly.

BMS16T ISSUE: There have been issues with that model of BMS. One fix for rapidly fluctuating readings (which throws things off) is to power the BMS from the Battery Terminals as opposed to powering it from the BMS harness itself. I dunno when you got your BMS' & DCC's but you should have also received an ISO Board for in-between the BMS & DCC (MUST be used if running DCC on (+) Side) and an external power adapter with a switch & filter.

1620041649648.pngISO BOARD:






1620041428485.png
External power board looks like this:
can't find a link to it.




Re bussbars... I pick on this as they are the cause of MANY AN ISSUE ! There are ridges & burs on the bars that must be filed off, this is from when they punch the holes through. They also most often have a light oil / wax coating to prevent corrosion etc. Just like the cell terminals often have oil on them leftover from Tapping or a wax coating to prevent corrosion as well. ALL of that has to be cleaned up. You would be surprised at how much trouble a bit of wax can cause. Burs, Ridges/Oil/Wax can all create troubles which appear as faults. FYI: I have several packs, my best performer (I call it that) uses 4mm x 15mm 110-Copper for busbars.

Here are My Chargery BMS settings. I run 2x174AH & 2x280AH so that is shown in the table below.
NB: I also have a QNBBM-8S Active Balancer on each battery pack which levels up the cells quite nicely.
QNBBM-8S Active Balancer from DeliGreen

Also I use a Midnite-Classic-200 SCC which I have programmed to allow for FLOAT to be utilized which helps with the cells being levelled up while preventing an overly high charge. Float will deliver the power the Inverter will demand and more (to the point of solar supply) while giving a lower VC charge to the battery pack.
Divide by 2 for 12V, Multiply by 2 for 48V
Absorb: 28.2 for 15 minutes (Called Boost ? for some SCC's)
Equalize: OFF
Float 27.9V (3.4875 VPC)
MIn Volts: 22.0 Max Volts: 28.7 (min 2.750 VPC - max 3.5875 VPC)
Rebulk Voltage: 27.7 (3.4625 VPC)
End Amps: 14A

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.


Chargery BMS8T Settings
SettingDefaultMy settingsNOTES
Over charge P Voltage3.653.65
Over charge R Voltage3.553.55
Over charge Current5086A / 150A0.5C rate for 174AH / 280AH
Over Discharge P Voltage3.002.65CUTOFF Trigger
Over Discharge R Voltage2.002.75Release @ this V.
Over Discharge Current300175A / 250A1.0C Rate for 174AH / 280AH
Low SOC cutoff20%0%forces cutoff @ % (faulty)
High Temp cutoff50C70C
Diff of Batt Temp1015C
Diff of cell Voltage30mv200mvUnmatched cells drift,
Temp UnitCC
Key BeeperONON
LCD Backlight1010min
Cut off Delay Time1010S
Current Calibration-SET-
Temp AlarmONON
Cell Empty Voltage2.502.50
Cell Full Voltage4.20?3.65
Default SettingEnable
Balance Parameter-SET- (OFF)*Passive is ON charge only, start at 3.40V, 30mv diff.
Battery Capacity AH1174 | 280Label Value of cells
Battery Power WH10004554 | 7168FORMULA (NominalVolts * #ofCells * RatedAH) (3.2*8*280=7168)
Low Temp cut off in Charge2C2C
Low Temp cut off in Discharge-10-10C


Hope it helps, Good Luck
Steve_S
 
In the BMS Config there are setting for Over charge Current. Have you adjusted those beyond the default ? which is defaulted to 40A I believe.
With 280AH cells they can take up to 140A / 0.5C-Rate.
Also make sure you are running the most current ....
Thanks for all the tips.... I think it is solved.

Two things I noted... my differential cell voltage was 20mv, and it is VERY likely that during charging with the behavior of the chargery powered from the sense leads that was tripping out the charge side of the DCC.

The other thing I noted was that when I turned on the AC supply to the Sunny Islands, after 5 minutes... they came on and started charging. I watched the current rise over a few seconds to >140amps (the sunny island was programmed to 140amp max) . I think I saw it get to 160amps on the chargery display and then I saw chargery disable charging side of DCC. The inverters threw the same fault code they did yesterday about voltage of battery being too high and powered off the AC side of themselves about 10 seconds. THIS THIS THIS is what I saw yesterday. This is exactly the behavior that I couldn't run fast enough to the inverter to see.

Here's the solution... it's on the SUNNY ISLAND side... Sunny island does not "sneak up" on it's max amps setting... it overshoots significantly. Since I'm using 280ah cells, I had set both the sunny island and the chargery to 140amps max. Sunny island blew right thru that limit and chargery killed it. My solution for the moment is to turn the charge current down to 90amps. I did this and watched it charge at 90amps for 10 minutes with no faults.

For those interested in the Sunny Island side of things, here's the settings I'm using.


Inverter/Charger Settings

Parameter Setting for LFP battery with SMA Sunny Island SI 4548 6048 US model

Battery Settings (221 #)
01 BatTyp Battery type VRLA (if you need to change this, you must long press enter when SMA SMA appears powering up inverter)
02 BatCpyNom Nominal battery capacity xxx Amp (name plate of battery)
03 BatVtgNom Nominal battery voltage 48V
04 BatTmpMax Max. Battery Temperature 113 F (45 °C)
05 BatTmpStr Battery start temp. following stop due to overtemperature 118 F (45 °C)
06 BatWirRes Power resistor of the battery connection in mOhm
07 BatFanTmpStr Starting Temperature for the “BatFan” function 104 F (40 °C)

Battery Settings (222 #)
01 BatChrgCurMax Charging Current of the battery 90A (never exceed 80% of your BMS max charge current)
02 AptTmBoost Absorption time for normal charge 6 Min
03 AptTmFul Absorption time for full charge 1 H
04 AptTmEqu Absorption time for equalization charge 1H
05 CycTmFul Cycle Time of full charge 180 Days
06 CycTmEqu Equalization charge cycle time 365 Days
07 ChrgVtgBoost Cell Voltage setpoint for normal charge 2.3v (2.2v-2.7v, translates to 52.8-64.8 16s, or 3.3v-4.05v per LFP cell)
08 ChrgVtgFul Cell voltage setpoint for full charge 2.30V (2.3v-2.7v, translates to 55.2-64.8 16s, or 3.45v-4.05v per LFP cell)
09 ChrgVtgEqu Cell voltage setpoint for equalization charge 2.30V (2.3v-2.7v, translates to 55.2-64.8 16s, or 3.45v-4.05v per LFP cell)
10 ChrgVtgFlo Cell Voltage setpoint for float charge 2.21V (2.2v-2.4v, translates to 52.8-57.6 16s, or 3.3v-3.6v per LFP cell)
11 BatTmpCps Battery Temperature compensation 0mv/deg
12 AutoEquChrgEna Automatic Equalization charge Disable

Hopefully I've seeded this with enough keywords to help the next poor sap.
 
Last edited:
Someone please delete my above post... I can't edit due to 400 minute limit and some changes need made....


Thanks for all the tips.... I think it is solved.

Two things I noted... my differential cell voltage was 20mv, and it is VERY likely that during charging with the behavior of the chargery powered from the sense leads that was tripping out the charge side of the DCC.

The other thing I noted was that when I turned on the AC supply to the Sunny Islands, after 5 minutes... they came on and started charging. I watched the current rise over a few seconds to >140amps (the sunny island was programmed to 140amp max) . I think I saw it get to 160amps on the chargery display and then I saw chargery disable charging side of DCC. The inverters threw the same fault code they did yesterday about voltage of battery being too high and powered off the AC side of themselves about 10 seconds. THIS THIS THIS is what I saw yesterday. This is exactly the behavior that I couldn't run fast enough to the inverter to see.

Here's the solution... it's on the SUNNY ISLAND side... Sunny island does not "sneak up" on it's max amps setting... it overshoots significantly. Since I'm using 280ah cells, I had set both the sunny island and the chargery to 140amps max. Sunny island blew right thru that limit and chargery killed it. My solution for the moment is to turn the charge current down to 90amps. I did this and watched it charge at 90amps for 10 minutes with no faults.

For those interested in the Sunny Island side of things, here's the settings I'm using.


Inverter/Charger Settings

Parameter Setting for LFP battery with SMA Sunny Island SI 4548 6048 US model

Battery Settings (221 #)
01 BatTyp Battery type VRLA (if you need to change this, you must long press enter when SMA SMA appears powering up inverter)
02 BatCpyNom Nominal battery capacity xxx Amp (name plate of battery)
03 BatVtgNom Nominal battery voltage 48V
04 BatTmpMax Max. Battery Temperature 113 F (45 °C)
05 BatTmpStr Battery start temp. following stop due to overtemperature 118 F (45 °C)
06 BatWirRes Power resistor of the battery connection in mOhm
07 BatFanTmpStr Starting Temperature for the “BatFan” function 104 F (40 °C)

Battery Settings (222 #)
01 BatChrgCurMax Charging Current of the battery 90A (never exceed 80% of your BMS max charge current)
02 AptTmBoost Absorption time for normal charge 6 Min
03 AptTmFul Absorption time for full charge 1 H
04 AptTmEqu Absorption time for equalization charge 1H
05 CycTmFul Cycle Time of full charge 180 Days
06 CycTmEqu Equalization charge cycle time 365 Days
07 ChrgVtgBoost Cell Voltage setpoint for normal charge 2.30v (2.2v-2.7v, translates to 52.8-64.8 16s, or 3.3v-4.05v per LFP cell)
08 ChrgVtgFul Cell voltage setpoint for full charge 2.30V (2.30v-2.7v, translates to 55.2-64.8 16s, or 3.45v-4.05v per LFP cell)
09 ChrgVtgEqu Cell voltage setpoint for equalization charge 2.30V (2.3v-2.7v, translates to 55.2-64.8 16s, or 3.45v-4.05v per LFP cell)
10 ChrgVtgFlo Cell Voltage setpoint for float charge 2.30V (2.2v-2.4v, translates to 52.8-57.6 16s, or 3.3v-3.6v per LFP cell)
11 BatTmpCps Battery Temperature compensation 0mv/deg
12 AutoEquChrgEna Automatic Equalization charge Disable

What I learned today is that as the SI finished charging and went to float mode, it also went to selling battery to the grid mode. The solution was to raise float voltage to 2.3v like the other settings.

Hopefully I've seeded this with enough keywords to help the next poor sap.
 
What version of the software do you have?

There were some changes in the recent updates that improve that bouncing cell voltage thing ..... The 4.02 manual also explains how to use external power instead of power thru the cell leads .... that helps that problem and improves accuracy also.
Version 4.04
 
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