Oups…This design with 432 chip (réf 1.25v)was already like this 8 month ago so sorry I think this is an early mod because there is no available LM4040 (ref 4.1v) on JLPCB
If you running nicely this design for 8 month it is perfect .
Thanks for clarify this
@stuart @Robert.Wall Do i understand correct that if i wire the relay to NC normally closed then without power the relay is closed circuit and when power Off = Closed Circuit and On = Open circuit in the rules page ?
I cannot answer for what happens inside DIYBMS, but for any hardware relay or contactor, the N/C contact is closed in the ‘normal’, that is the un-powered, state. For the N/O contact, it’s open in the un-powered state and closed when the relay is powered.
Stuart must tell you how the state of the relay (powered or un-powered) relates to the logic.
Hello Stuart,
My first post here, will this new DIYBMS v4 support 18050 battery bank with 14S80P?
And LTO bank with 24S2P (max voltage at 64.8v)?
You betcha!
Both old and new controllers will support that configuration. I’ve recently designed some boards for LTO style voltages and they are being tested by a couple of forum members - take a look at DIYBMS for Lithium titanate battery cells (LTO) - #11 by stuart
First, @stuart thanks for your help.
I have already been able to make a module work, I have tried several plates one by one, but when I try to put two or three in series it only shows me one column, the cables I have checked. Each separate module shows the battery, joining them not
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Ok, have you gone to the settings and selected how many modules you have?
Why is the temperature wrong? Perhaps a soldering issue on the ATTINY chip?
im having same issue i believe …
@stuart
i was able to flash newest firmware. But now if i connect more then one board, it only shows one and on top of screen indicates “Controller found (2/3/4…) modules, but is configured for 1.”
AND in settings if i set how many numbered of series cells, about 20sec later just reverts back to 1
when i set number of series cells the green leds on modules will flash once “in sync” one after the other like they should. they also do the same on initial power up.
so the controllers see’s all the modules but wont save the number of series cells i set in settings…
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.
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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).
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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)