JK 4S BMS brand new with errors

[upnorthandpersonal]

These chips are the likely culprit:



You can replace these with a STI3470 (or JW5352M) and that should fix the CPU AUX Anomaly. Not sure why you have the "temperature sensor is abnormal" warning. That either means the sensor was disconnected when you took the screenshot, or the sensor is bad/badly connected.

You can PM me your address and I will send you some replacement chips. You do need some soldering skills with SMD components, preferably with hot air.

 

[Vadim_EL]

upnorthandpersonal Thanks for the quick response, those chips you marked are labeled (BCE1H). I would have been looking for what burned out for a long time, thanks for the prompt. We have where to buy them, yes, I have a lot of experience in soldering, thanks again, I’ll buy it and try to replace it.​

 

[Vadim_EL]

ordered these DC-DC after tomorrow should come. I measured the voltages incoming and outgoing from these DC-DCs, one comes out 3.3V from the other 4.5V. Something I haven’t met who needs 4.5V

 

[Vadim_EL]

I replaced the one that gave out 4.5V, nothing has changed. Then I calculated the volts, it turns out that all volts are correctly issued.

Vout=0.6*(1+R1/R2)
R1=104(100kOm)
R2=153(15kOm)

Vout=0.6*(1+R1/R2)= 4,6V
===================================


R1=683(68kOm)
R2=153(15kOm)

Vout=0.6*(1+R1/R2)= 3,3V
=============================
Do not know what to do now, maybe it's a reset button need pressed? but no buttons at all

 

[upnorthandpersonal]

What exactly did you replace it with? Chip type? It still reads BCE1H in your picture.

 

[upnorthandpersonal]

Also, what version of the App are you using?

 

[Vadim_EL]

I replaced 2 of them from one side - 1 and the other side - 1
S47Bcj4 - the new
=====================
1 year I use - enjpower-bms-3.7.4.88
but now I install - 极空BMS_4-9-2.apk , the last app what support android 6

 

[upnorthandpersonal]

S47Bcj4 --> got a datasheet? Can't find that reference anywhere.

 

[Vadim_EL]

https://datasheet.lcsc.com/szlcsc/2001060933_TMI-STI3470_C478938.pdf

 

[upnorthandpersonal]

Ok, STI3470. That one should be fine. I would suggest replacing them all. One of the issues with the original chips in some versions was that they had a 500kHz chip instead of a 600kHz one, and that messed things up. I had a similar situation where the output voltage was fine, yet the issue was fixed replacing the component. I'm not saying this is definitely the case, but if you have them, worth a shot.

There could be another chip that needs to be replaced when this issue occurs. I need to go check my notes, it's been a while...

 

[Vadim_EL]

I think know the problem.
smd component marked as r3dlb. do not know what is it, can't find datasheet. But IN +3.3 , out 2.0V
but A13 Amplifier (lm321) need supply from 2.7

 

[Vadim_EL]

I think it's 3V Voltage Stabilizer. in front the same

 

[upnorthandpersonal]

Might just be an LDO.

 

[Vadim_EL]

I soldered the diode instead of the LDO, now the A13 is powered by 2.9 Volts. But nothing has changed. I'll put this idea aside for now when I gain more strength =)

 

[Vadim_EL]

I understood what happened, hk32f030mf4p6 was short of 3 volts, R3D is all working. I desoldered (hk32f030mf4p6) and 3 Volts was restored, signals from the T1 T2 go to hk32f030mf4p6. I don’t know if I can read (hk32f030mf4p6) and flash new one.

 

[upnorthandpersonal]

I wonder what could have happened that made that one fail... very odd.

 

[Vadim_EL]

this capacitor is gone, it may have been poorly soldered, I don’t know if this could lead to a breakdown

 

[nvbt]

Hello? I have JK-BD6A17S8P and the same problem (Protection (CPU AUX Anomaly)). I use it in battary for scooter. External Temp sensors have 9.4kOm, voltage to sensors 2V. I do not think it's sensors problem.
==============================================
help me find the cause, where to look? I think all bms are made according to typical scheme, please indicate where to look for the cause of the malfunction, thanks.
All power mosfets are - serviceable, I test it.

Mine B2A8S20P has unmarked 10 pin chip in package smaller than SOP near this place.
I have already 3 bms with such malfunction.
They are more or less working, except something happens with current reading and hence with SOC as well. Also, one bms which is on a tricycle (small ev) deny to charge it, probably because due to bms disconnecting a charger, that is why it stops charge battery.

 

[Seal]

The continuation of the story with "CPU AUX Anomaly" without happy ending.

I replaced all three chips with new STI3470.
BMS "works" - it shows correct data, I can change settings, etc.
But while charging it continues repeatedly reboots (maybe not so frequently as before), but with another error
[Abnormal coprocessor communication] [Abnormal cancellation of coprocessor communication]
I've seen some posts here and here with such error, but it seems that there is no solution for it.
Also I saw only two sources with this error in the internet - this forum and esphome-jk-bms github.

---

@upnorthandpersonal, thank you very much for helping!
Maybe sometime in the future I'll return to this BMS and try to figure out what is the problem.
But winter is coming and now the best solution seems to just replace it with an another one. Definitely not JK))

 

[upnorthandpersonal]

If you want/are able to send it to me at some point just DM me. I can check it out in detail.