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DIY Lithium Battery Balancer and monitoring (BMS)

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Hi,
Will anyone be selling these on tindie or anywhere, dont have time to do it all myself but would love to have a couple (10 :D)
Regards

I have seen other people mention similar behaviour but I’ve never managed to reproduce it (and therefore can’t fault/debug). Folks have had these DIYBMS devices running in sheds for 12m+ without bother so its it must be down to a difference in WeMos units or similar.

@stuart
Thanks, yeah i am not sure what is happening, i may try and order another nodemcu, but make sure i get one that is similar to the original one i had.
I am wondering is there away to remove the wifi part of the wemos and have it directly connected to a laptop which is then connected to the internet.

How did you get around this problem, as i also have the same issue.
Also which why do you do connect your wesmos, ie to the repeater or router.
Thanks
Andy

Hey all,
Just found this thread via another forum, I’m about to order a batch of the V4 BMS and so I’ve panelized the Gerber files for V4 to get more value out of the cheap JLPCB (etc) 100x100mm

(effectively you’ll get 4xBMS for your money now).

Feel like I need to squeeze something in the gap, any suggestions for related projects/gerbers that would fit?

Can provide the zip for the panel if you want it for the repo.

Nice work, you can just tick the panel open on jlcpcb and they will do this for you!

Indeed, but they’ll only panel the same gerber in the same orientation with a footprint of 70mmx70mm or larger - essentially you’d get 6xBMS per panel, but wouldn’t be able to use the ($2) 100mm x 100mm option
(and incur an engineering fee).

Stuart have you looked into using a dedicated ic like the LTC6813?

No I’ve not. Its an expensive chip to have a play about with (about $30 USD)

Yes you can.
Upload the Gerber
Select “Panel By JLCPCB” and X=2 Y=3 (giving 6 PCBs per panel)

Panel size is X: ( 50 x 2 )=100.00mm Y: ( 30 x 3+ 10 (Edge Rails) ) =100.00mm

They V score the panel so you can break it apart and the cost is still only $2 USD
If you increase the number of PCBs to 10, they only charge $4 USD

This way you should get 60 modules for $4 USD

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awesome stuff, thanks

Hello all. Thanks for all your time and energy into this project. I am having an issue with v3.
Modules disappear when I try to provision a second module. First module is fine. My understanding is to leave the first one connected, then connect the second one to the first one and provision again. When I do this, the module acts like it has been provisioned, but the web reference doesn’t show the second mod or the first. When I disconnect the second, the first reappears.
My cable is + to +, sda to sda, etc. Am I dealing with two modules with the same id?
If so, what’s the fix? I will search through the previous posts for something.


I also don’t see the provision tab when I click on the module tab in the web page.

i did that and they contacted me to ask for more money (Hi, the panel is no more than 100*100mm and it needs you to pay for extra board fee 6.1$ . If the extra fee haven’t been paid ,the order will be cancelled for you in 2 days.Thanks!)

I made and ordered this panel in the end (happy to supply gerbers)

as I had similar issues.

thanks but they already started production on the controller so all i need is the smaller one

Ok, I’ve got the hardware dialed in. After a couple of bricked attinys and a some 710’s replaced, I’ve finally got the cell modules good. I can’t see any modules on the web interface. I’ve flashed my Amica Node MCU controller with the correct settings (again), and went through the wifi setup. The controller connects to the Management console, and everything works --But, there are no modules showing.
My only assumption might be a software issue for me. Though I have only limited python skills, I guess I will dig through the code to see if something is wrong.

Fred, are you referring to the V3 boards? If so, did you follow the provision process?

Yes, V3 boards and I believe so. I’ll give a brief history of my process maybe someone can figure out what went wrong/not done correctly.
I assembled 6 boards (I only need 4 currently). The only issue was that the 710’s had no pin 1 markings so I toasted a couple before I figured that out.
I programmed the Amica NodeMCU; went into my network; saw the DIY bms; web interface connection went smoothly.
Found my card’s IP; went to the management console.(In Windows Edge browser)
Built a shield for my Amica with 2 2k2 pullup resistors; attached one cell mod to the controller.
Went back into the management console and couldn’t get the buttons to do anything so I opened up seamonkey and got to the #modules screen.
Clicked the provision button. Controller light lit up, seconds later the cell module light lit up and after a moment, both the cell module and controller were blinking together (the cell module LED was very faint).
The first cell module then showed up in the management console (yes!). Leaving it connected, I attached the second cell module to the first cell module; clicked provision; and got the identical process as the first. Both were successfully provisioned.
The second cell mod didn’t show up. I tried everything (even bricking attinys. p.s. use the eeprom_clear under attiny in Arduino examples, not the other one).
Reset both cell modules (clear eeprom, burn bootloader, load cell module script)
Reset the controller with the esptool.py file process and reloaded the controller script; went through the process again of signing up to my network. (successfully)
Connected one cell mod to the controller; opened up web interface; provisioned cell mod (appears to be successfully), Nothing.
I did see just before clicking the provision button, the Titles of the columns (i.e.Module
id, Current Voltage, Voltage calibration, Manual Calibration, Temperature Bypass, etc.) but they disappeared after the provision process.
Here I am. One cell connected with no way to monitor it.

No luck. I’ve reset both the controller and the module to ‘factory’. Then, using Arduino 1.8.5, successfully loaded both scripts (including the bootloader on the mod; bootloader first).
Successfully provisioned but nothing on the Management console.

Ok, this is what I see without cell module connected to controller:

And this is what I see when cell module IS connected to controller: