Proton wrote: ↑Sun Feb 23, 2025 4:50 pm I am lost here:
I click on the first link and BMS firmware binary but I ncannot click it.

I think you just need to login to github and you will get download icon next to the artifact.

I've updated all boards to the latest firmware again CI #21.
Board #4 is slowly flashing and reporting opmode error and lasterr BALANCER_FAIL.
It also reports 0V on all channels.
balancer_failed.png

Turned off balancing for now on all boards as this reading affects total reading.

I think that ...

PetersonOctavius wrote: ↑Sat Feb 22, 2025 2:36 am all the other lines are reading just fine

Why do you use different code for min and max? It's the same thing just on different bytes. So, code for min should return correct value for the max if you read from bytes 2 and 3.

CAN mapping for ISA shunt is working nicely after configured correctly.
Here is configuration for idc and power:

Ah yes, the newer firmwares have a POST (power-on self test) and apparently that fails. This is indicated by the slowly flashing LED. In "lasterr" you can see why.
On said module there is probably an issue with the i2c comms to the ADC. Of course I don't understand why it shows now. I have ...

Few more days passed, and here’s the latest status...

Good news: Delta is dropping by about 1mV per day.
subvalues205247.png

I raised cell voltage from ~3.7V to ~3.9V and ignored delta changes in between. Now I’m keeping it between 3.85V and 3.92V to make it easier to track delta differences ...

johu wrote: ↑Tue Feb 18, 2025 10:06 am Interesting, I could change the sequencing so it doesn't scan 0,1,..15 but 0,2,4....15,13,11,...1 . So less potential jumps

Sure, if you think it's worth it. Happy to test it out!

What happened to 1.09 though? Looks like it was discharged too much? Also 2.00 is flickering. Is the connection good?


Could it be somehow related to the last and first series in the pack?
I managed to get screenshot with this behaviour on cells between boxes 0-1, and 4-5.
I can't catch it on ...

What happened to 1.09 though? Looks like it was discharged too much?

It's actually 1.08, and it has been the lowest cell since the first measurements. I manually charged it a bit earlier, but apparently not enough. The "hole" in the graph above 1.08 makes the difference look bigger than it ...

Status update after 24h:
https://drive.google.com/file/d/1GGfthETUmseFeljjOBOEQ9nLlaD1npYz/view?usp=sharing

And here’s the chart for the last 2 days, after charging to cca 3860mV:
batt2day.png

I wanted to pull out balance states durations for each cell. Since I have detailed logs from BMS for ...

Great visualization! Will be interesting to see how long it takes to even out the rest. I take it one box is 1mV?


Thanks. I'm still learning, but you can do amazing visualization with Grafana charts and loads of data for them.
It's not one box for 1mV, it really depends on the delta and with ...

Finally, I got all boards working… actually, they’ve been running fine for a few days now.

The issue with the last two channels on board #4 turned out to be bad solder joints on some of the replaced resistors. A second pair of hands and eyes caught it, and once fixed, everything started working. :D ...

johu wrote: ↑Wed Jan 29, 2025 10:10 am Ok, could it be it's because you measure in circuit? Is the 5V rail at the correct level? If so, don't change them.

I don't know if it's because measuring in circuit... I just know how to put probes on the pins and read value.
Thanks, I will check 5V rail level...

johu wrote: ↑Wed Jan 29, 2025 6:35 am Yes, the BOM on Patreon is a bit outdated, will update. The values should be R9=100, R12=10k, R16=51k

Thanks, that makes R9 ok as it measures 100R, but other two not. I measured R12=8k5 and R16=12k2

I wanted to follow up on my last message...
I ordered and received the components and have now replaced all the resistors I previously identified as bad. The latest voltage readouts from all boards are available in the "0128_1800" sheet in this document:
https://docs.google.com/spreadsheets/d ...

I've received the P- and N-channel MOSFETs and replaced all six components from my previous messages.

After the first attempt, I got these readings:
u0 1.15625
u1 0
u2 3894.46875
u3 3895.03125
u4 3894.46875
u5 3866.25
u6 3903.25
u7 3886.21875
u8 3902.6875
u9 3835.71875
u10 -177.34375
u11 403.46875 ...

I ran a diode test on the FETs. Most measured about 0.585 V, but I got a “beep” on four of them
- Q39
- Q11
- Q87
- Q81 At the moment, JLC is the only source that has these parts in stock. If there are no other suggestions, I’ll go ahead and order replacements from them.

I managed to desolder Q1 and Q5 myself using a hot air gun - new skill unlocked! :)

After reconnecting the BMS to the battery, I’m still seeing problems:

image.png

Not all channels are functioning correctly. I don't know whether this is due to the missing components or if other parts are also ...

Yes, I had battery connected all the time. Do you think disconnecting battery on firmware update should help avoiding this issue?

I'll need to bother my friend for removing components, these two, right?

Last night, I checked the modules’ temperature by hand after powering them off (but still leaving them connected to the battery box).
Module #4 was hot - I would say: similar to what happened with module #2 back in September, which had a shorted MOSFET. I’ve now disconnected all modules from the ...

As mentioned in the main BMS topic, I've update firmware to 0.20.B and connected one NTC sensor to the first BMS board and Temp1.
Working great and showing what I think is correct temperature - around 16 Celsius degrees.

On first two boards I've managed to upload firmware using web UI and can, but ...

I've updated first board with 0.20.B firmware and have there one temperature sensor for testing...
Reported value looks good with default settings.

For now, I will charge only 2 lowest cells. That should result with packs divided in two groups with roughly the same voltage... first three packs in one group and last three in the other. Delta between those two groups should be around 80 mA and that should not be the problem for my low usage ...

On a pack of this size balancing might take too long. I'd guess there's like 5 Ah between the lowest and the highest cell. And the balancer is only connected to 1 cell at a time per module. So the 100 mA balancing current is effectively just 100/16=6 mA when all cells are balanced. That would be ...

After two days, here’s an update on the battery:

I’ve added a new sheet called “balancing” in the first document, showing two additional cell voltage measurements:
https://docs.google.com/spreadsheets/d/1Qhn3T-IRCJ9HANdoSaukVrbah46u_7uPyooNAfzuMDA/edit?gid=512643139#gid=512643139

I also created a ...