How strange, do you get the green “settings saved” message when you click the save button?
What version of the code are you using?
Latest master release is
Version: 7abd4d259381f981bc5a0f8cb148c391253a01db
I recommend following the instructions on GITHUB to program the controller (you don’t use platformio).
The temperature is due to the lack of resistance R20, it was not well welded, and if I select 2 modules in configuration but only configure one with data
I really like the mounting brackets;)
Could you share the scematics for the powelines here? It looks like the solar feed in positive is always connected to the multiplus u unless the breaker was activated? Thanks!
@Jon_Coop I’ve flashed the code from GITHUB to a 4MB Wemos D1, and I cannot get it to behave as you describe. Did you see the previous post about the green “settings saved” message - do you get that appear?
I wonder who made those 
but i have to make more since as i said mine brakes for no reason. They are printed in PETG because PLA will deform at 70C when the modules are in bypass.
Sure the schematic is this :
And yes that is a trick to be able to shut it all off from the main circuit breaker. Bear in mind that i have made a mistake on the photos where i have mounted the fuse on the negative side (i need to fix that). Also i haven’t powered the MPPT charger yet (i haven’t mounted the panels yet).
I would raise the cell under voltage to around 3.175. There isn’t a lot of capacity below this voltage with LiFePO4. If you have the battery spec sheet you want to stop discharge right at or before what is called the knee. This is the point where past it the voltage falls off fast, almost straight down.
The cell over voltage looks good. No real capacity gain above that voltage. LiFePO4 batteries stay pretty well balanced once the initial balancing is done so the bypass voltage looks good. Once the packs age you may need to drop it down so the packs stay balanced.
@stuart one installation like this with communication between your BMS and the victron, it was wonderful !!
is possible to implement ?
you mean using CAN or what are you referring to ?
yes, VE.Can for CAN-bus (BMS)
but you can use diyBMS with 2-wire bms so you don’t necessary need CAN but yes it’s nicer with CAN, you get more info and control.
Thanks i will looking at this better this weekend, look very nice!
Have i killed a cell module?
Reverse wired, now its giving incorrect readings?
It may of just cleared out the EEPROM memory of the module/attiny processor. Try reprogramming it again and see if that helps.
Thank you Stuart, i think its ok now, i just re calibrated all packs to my multimeter and it now looks like this
2 modules are giving incorrect temps, but i shall worry about those another day.Ok, that is strange though! Are these V4.21 boards from JLCPCB ?
yeah but i had to fit the thermisters, im guessing that i screwed up the thermy soldering on pack 2, and pack 6 was ok until i cross wired it, suspect that board needs replacing now, but will monitor it and see how it goes.
Ah, ok, explains it, those parts are TINY !
Hello, I missed something and probably it is something stupid. But last year I made a proof of concept with “white” controller software and everything was working fine with Lion
This time I updated to latest software (even moved from PlatfromIO to suggested ways on GitHub - stuartpittaway/diyBMSv4Code: Software for diyBMS v4, especially as couldn’t figure out how to do hard reset on Wemos to forget old wifi pass). It is Lifepo4 battery now and thicker ~22awg cables.
