DIY Lithium Battery Balancer and monitoring (BMS)

I dont think you uploaded your latest code with the new temperature code

Ah your right it had gotten a conflict when i made a change directly on the github website. I’ve resolved it now so it’s showing on the repository ok now.

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Thanks. I put in the values of my 10k thermistor into the code.
0 c the value was 32014
and 100 c was 697.22
Are the temperature supposed to be close to actual temp because it was reporting 30 degrees and I had to use the manual config to get it down to the actual temp of 22 c.
Here is the data sheetNTC_Leaded_disks_M891-1317157.pdf (529.6 KB)

Mine are close to the actual temps, have you tried the code without any modifications to see what figures you get?

Yeah i was getting around 850

I mean my latest version of the code without changing the values. I was getting around 730 on stuarts code which equated to 22 degrees or so. If the stock values do not work you may have to play with the figures if your thermistor is significantly different.

I have not tried the stock values. I just went with the info in the data sheet. I will try it tomorrow. Have to go to bed its 11.37pm here in California and i have a math test tomorrow lol

If you are using the same component, you shouldn’t need to change the code configuration.

Perhaps you need to modify the calibration numbers in the web interface?

I am using the epcos thermisitor which is different than the one Collin is using. I put the numbers in from the data sheet and the temps were too high, so I did have to modify the calibration numbers in the web interface. It seems for Collin that the temperatures were close to actual without adjusting the temp calibration.

Nice videos on youtube Colin!!!

Thank Joey, hoping they’ve been helpful to people. Are you up and running with your setup?

I have almost everything except the load resistors now, waiting on 2 more smd components and then i can start soldering! Can’t wait haha.

I’m also looking into what i want to use as a means of readout, grafana seems interesting!

I also couldn’t wait. Only had the smd resistors and attiny85 and started testing without the caps and diodes. Also didn’t have the jst connectors.

I have 3 boards on my bench connected using the ICSP header. SDA/SCL are available on the ICSP header and just add GND and 3.3v to Vin and reset. It does work and it’s enough to do some influxdb and grafana testing.

I did run into some problems using Colins fork so I copy and pasted the Influxdb part into stuarts latest code. Then I ran into a problem with the ESP8266 not starting the webgui and did a small bugfix. It’s a bit guerrilla style but all is working fine for the moment. Even without the caps and diodes. But just reading cell voltage for now.

You can find my fork at: https://github.com/CuriousTimo/diyBMS

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What issues did you run into out of curiosity as it’s working great for me, that would have been a lot of copying and pasting also as it took quite a few modifications :slight_smile:

For others trying to do the same - don’t link multiple circuit boards/modules together without the ADUM chips - you will destroy the components by pushing high voltages across them!

The modules wouldn’t show up in the webgui after I pressed provision. From memory I could see them being found in the serial monitor.

In Stuarts code I moved scani2cBus() to after the Wifi setup and init.
But I did a lot of testing and debugging and I could give your code a try again tonight.

I’ll try and get back to you.

On a different note… not related: I have also changed R2 to a value of 510R.

After i provision i just had to go back to the main page and they showed up straight away, this was the same in Stuarts code also. BTW you may want to host the loader.js page on your github also if you are not going that already as i had to host that myself on my github after i modified it to support the grafana configuration options so as i change my code/loader.js it may break yours.

Colin, I tried you code again…

In the serial monitor I can see all 3 modules. But they don’t show up in the web interface.
Tested on macOS using Chrome and Safari.

Something is weird there as the temps are not reporting for you as well.

Strange as the code is working well for a few people now.