@johu, I’m unsure if this is the right place to post since it’s a continuation of the previous discussion. If not appropriate, I apologize—feel free to move the post.
I manually checked the voltages multiple times before connecting the BMSes, and everything looked fine. All values measured on the BMS connector were as expected. Though I used a basic multimeter and rounded values while writing them down, they seem consistent. In the first sheet ("manual"), the orange columns show the manually measured values, while all other values are calculated. Total voltages match both box manual measurements and the values received from the ISA shunt.
I performed multiple CAN status reads for each BMS using the oic tool. The second sheet ("can") includes a comparison of these reads with HV battery connected and disconnected. The devices with expected values are marked in green (bms1, 4, and 6). However, devices 2, 3, and 5 return strange values. Additionally, I noticed that part of boards 2 and 5 gets unusually hot - over 110 celsius degrees.
To rule out HV battery wiring issues, I tested another battery (5 cells) and confirmed that devices 2, 3, and 5 still report invalid readings, while 1, 4, and 6 behave correctly.
Any help figuring this out would be greatly appreciated! Let me know if more information is needed.
As a side note, while testing with the other pack, I captured a thermal camera image of BMS 2, showing the location of the hot area. I also measured that my RPi5 + RUT956 consumed about 450 mA at 12V (likely 250 mA from the RPi and 200 mA from RUT during 4G connection). The six BMS units consumed another 200 mA collectively.
Short video with everything connected and then BMS disconnected, left only rpi and router.
- thermal
