Hi, if you have built 30 modules and 2 are not working as expected then there must be a bad soldering joint, do you have a magnifying glass?
If the voltage is wrong and no temperature reading it suggests that it’s the voltage reference chip.
Thanks Stuart, it didn’t look like it, but there was indeed an Attiny pin on each of the modules with bad contact.
Now I have 30 cell modules, which is good because being able to attend two 15S installations, mine and a friend’s.
5 posts were split to a new topic: Module report zero volt and -40 temperature
My system is working using DIYBMS
Thanks for helping Stuart
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So far I am pretty impressed, I moved my nissan leaf batteries to my shed, and although I am still waiting for a half decent solution to charge my test setup, things look pretty good.
I found my own mistakes in soldering and programming. Lost a virtual computer running grafana and influxdb for a day or 2. found things I can an cannot do with 3d printing mounts and I have to wait sometime to be able to get some dinrails.
Still I would like to share some graph. I graduatly drained to cells with 0.01 volt per night to get them pretty much balanced. I am impressed with how much the cell modules are able to bleed off, even when you set the temperature tresshold lower then the 65 degrees.
Thanks Stuart!!
I am powering the ESP from a dc-dc powered by my main 7s pack. The ESP with the standard program is rather power hungry (70-80ma @ 3.3V). I have several other ESPs running with an average of ~30ma. They are taking advantage of the modem sleep modes and delays in the code allowing periods of ~15ma consumption during idle followed by periods of ~70-80ma during mqtt transmission.
If I force the modem to sleep (wifi.forcesleepbegin()) the current drops down to a steady 20-27ma. Adding in any amount of delay into the main loop seems to cause a crash of the program…not sure why, it just appears to be resetting. There should be a lot of dead time between the tx/rx packets and other updates which could take advantage of sleep.
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Does the controller web interface still respond to requests when in sleep? Does it automatically wake up when a web page is requested?
Hi Stuart
Where is the Min, Max voltage range in the web front end hiding now,
I found this in the thread but it seems the file is not been used anymore,
That’s been added back into the next release
No, the wifi.forcesleepbegin basically turn off the wifi, so no webpage is available. It does seem to still work as the lights flash and look correct…just no webpage. It was just a test to see the power if the wifi is turned off.
Any idea why a delay() added into the main loop causes so much problems? I am okay having a slower update of maybe 10-20seconds between cell updates as needed.
wow! That looks really good. I am planning to make a tree 6p13s packs. If that works well, I’ll make another 3x 6p13s config. As the cabling is a lot of unnecessary work and the stacking looks really good, I’m wondering if we can make a stackable version that automatically connects Data between the stacked modules. Even more helpful would be if one of the battery contacts could also be passed between the stacked modules, so that we’d only need one contact/plug for each cell in series 
Just to repeat what’s been mentioned before, the modules are designed to be as near to the cells as possible, using short power wires to keep resistance low.
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Is there a difference between the software version v2020.11.02 and v2020.12.16?
No, I’ve been experimenting with github actions to automatically build the code and release it - this was just an example/test. There are major code changes coming soon though.
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Hello Stuart, at first thanks a lot for your work. I use your BMS since 3 months with an 48V 200Ah Bank without Problems. Since i have changed the Power inverter i have problems with the communications of the controller with the modules. During the measering with an oscilloscope, i have killed the controller. Now i load the last version from github to the new controller and the controller starts up, i can connect with him, but it doesnt show the menu to set the SSID Name and password. I only see a white screen under the adress 192.168.4.1. He outofill /softap.htm behind and nothing is visible on the page. I`ve checked it with different controllers.
I bet you didn’t upload the file system image?
Many thanks, this was the problem. I have never known, that this must be done. I have a complete new installation oft the Visual Studio Software…
Have you seen the YouTube videos I did explaining how to program the controllers using VS Code ?
6 posts were split to a new topic: Workaround for the communication problems