JBD bms switches on and off continuesly - param "FET ctrl" - solved!

[kumpactor]

Hi,
I also face the problem JBD switches battery on and off, as some threads here report.
My bms switches continuesly with a period of 1s when connecting load.
Neither JBDtools nor app XiaoXiangElectric show any error.

I'm building a battery from 16 cells EVE 280Ah and bms JBD AP20S006 (bms upto 20 cells, 300A contactor).
During last three days I just discharged the battery for testing with 4 bulbs a 12V 50W for a few hours.
Everything was ok, contactor switched on when connecting load, JBDtools reads and writes configuration, app XiaoXiangElectric shows bms status and all 16 cell voltages were correct.

I wonder if the bms is sensitive about connecting the cell wires: First time connecting upper cells (lower cells connected first) there was a spark on the left side where the red wires are.
Next time when it comes to connecting the bms, I first disconnected the red wires from cell 16, then plugged in upper cell connector, then screwed cell 16 wire to battery terminal. There was a small spark at the battery.
I disconnected and connected 2-3 times, last time there was no spark anymore and the bms switches on and off continuesly.
Pins still look ok.

Do other JBD users also noticed a spark?
Did I destroy it or was my bms DOA?

All wires are well connected. Cells voltages are at 3.26V each, bms calculates SOC to 20%.
Total voltage is 52V, no drag under load.
The bms configuration was not changed when the error occured, but to make sure I restored factory configuration using JBDtool.
All voltages are within range. And default delay for voltage or temperature range violations are 2s or more, here period is definetly 1s.

Any idea how to find the reason the bms switches off?
Can JBDtool show more detailed error info than green ticks on the info page?

Any help is appreciated!

 

[kumpactor]

Did further investigation.
The OverkillSolar JBDtool, when connecting load, shows the "Protection count" of "RSTnum" as 1.
What does it mean?

And bms also refused to charge. Connected a power supply, the bms connected (contactor switched on) for about a second, then turned off and stayed off. Charge current dropped to 160mA. SOC still at 20%, all cells 3.26V.
Using 25mm2 wires for cell interconnection, checked each connection at each cell with YR1035 to be under 0.2mohm, measures directly to cell (the terminals with 2 the holes).

Is this a feature I dont know of?

Thanks for your help!

 

[42OhmsPA]

Did further investigation.
The OverkillSolar JBDtool, when connecting load, shows the "Protection count" of "RSTnum" as 1.
What does it mean?

And bms also refused to charge. Connected a power supply, the bms connected (contactor switched on) for about a second, then turned off and stayed off. Charge current dropped to 160mA. SOC still at 20%, all cells 3.26V.
Using 25mm2 wires for cell interconnection, checked each connection at each cell with YR1035 to be under 0.2mohm, measures directly to cell (the terminals with 2 the holes).

Is this a feature I dont know of?

Thanks for your help!

What are your undervoltage and undervoltage release set points?

 

[TomC4306]

wonder if the bms is sensitive about connecting the cell wires: First time connecting upper cells (lower cells connected first) there was a spark on the left side where the red wires are.
Next time when it comes to connecting the bms, I first disconnected the red wires from cell 16, then plugged in upper cell connector, then screwed cell 16 wire to battery terminal. There was a small spark at the battery.
I disconnected and connected 2-3 times, last time there was no spark anymore and the bms switches on and off continuesly.

Bms cell sense wires should be connected to the cells with the connector NOT PLUGGED IN. The fact that you connected and disconnected two or three times and then it finally stopped sparking might indicate that you bricked the BMS.

 

[kumpactor]

Values read from BMS by OverkillSolar JBDTools V2.9-20210524.exe are:
CellUvp 2200mV Release 2700mV Delay 2s
PackUvp 35200mV Release 43200mV Delay 2s

Should be fine; and the tool does not show a Cell Uvp warning (?)

 

[kumpactor]

Bms cell sense wires should be connected to the cells with the connector NOT PLUGGED IN. The fact that you connected and disconnected two or three times and then it finally stopped sparking might indicate that you bricked the BMS.

Please excuse my wrong description, all wires are screwed to the battery terminals. I will attach a picture.

So, you also get a spark when plugging in the cell wires to the bms?

Is it maybe a firmware problem and there is an update available?
Tool reports:
HardwareInfo: JBD-AP20S006-L20S-300A-B-U-R
Version: 2A
Production: 06/06/2022
Manufacturer: DGJBD

 

[TomC4306]

So, you also get a spark when plugging in the cell wires to the bms?

No, I've never seen a spark.
After connecting all of the cell wires and BEFORE plugging in the connector to the bms, did you check the voltages at the pins first?
From pin 1 to 2 - 3.2 volts, pin 1 to pin 3 - 6.4 volts, 1 to 4 - 9.6 volts et cetera.

 

[kumpactor]

Solved!
Thanks for your time!

If using a JBD BMS with contactor, like AP20S006, watch out for the setting of the parameter next to LED. It has no readable name in english translation of tool JBDTools V2.9-20210524.exe
It is the delay in seconds of the contactor beeing switched off after load has been disconnected.
If set to zero, contactor is switched off although the load is still connected.
If you set to value to e.g. 10, contactor is switched off 10 seconds after disconnecting the load (testet).
If load stays connected, contactor keeps switched on. Test: After 20min disconnected the load, at 20mins 30s the contactor switched off.

In bms_tools_jbd_windows_v1.1.4.exe the field is named "FET ctrl".
I've never touched the field.

The first tool I connected to bms was bms_tools_jbd_windows_v1.1.4.exe.
And first action I did was reading the configuration from bms and storing in a file. The file contains:

fet_ctrl_time_set 0

But the bms worked the first three days including reading and writing configuration. Strange ...

 

[Quattrohead]

Yeah I came across this too.

 

[patrickza]

Solved!
Thanks for your time!

If using a JBD BMS with contactor, like AP20S006, watch out for the setting of the parameter next to LED. It has no readable name in english translation of tool JBDTools V2.9-20210524.exe
It is the delay in seconds of the contactor beeing switched off after load has been disconnected.
If set to zero, contactor is switched off although the load is still connected.
If you set to value to e.g. 10, contactor is switched off 10 seconds after disconnecting the load (testet).
If load stays connected, contactor keeps switched on. Test: After 20min disconnected the load, at 20mins 30s the contactor switched off.

In bms_tools_jbd_windows_v1.1.4.exe the field is named "FET ctrl".
I've never touched the field.

The first tool I connected to bms was bms_tools_jbd_windows_v1.1.4.exe.
And first action I did was reading the configuration from bms and storing in a file. The file contains:

fet_ctrl_time_set 0

But the bms worked the first three days including reading and writing configuration. Strange ...

Bringing this old thread up as I have a similar problem. Is there any way to set this using bluetooth?

 

[kdiver58]

Bringing this old thread up as I have a similar problem. Is there any way to set this using bluetooth?

I never found a way .. I disconnected the blue-tooth module and connected mine with a UART box by running jumpers. I later on ordered plug ends to make the connections easier. Here is my thread on the problem.

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[kdiver58]

 

[patrickza]

Thanks for that. I was hoping I could solve it without having to wait a week for a delivery. Pity they don't make everything possible on bluetooth.