DIYBMS v4

Ah ok. What you look for is whats generally called “limit charge” or something like that. A function that can reduce charging so that balancing can catch up. Even though it can made with rules as such and its rather simple to add another rule its often better to use RS458 or canbus depending on inverter and instead talk to the inverter. Though this require alot more coding.

Im currently using an ESP8266 that sits in between doing that kind of job in my system. Ie i have attached an ESP8266 on each of my device that talks MQTT and then is controlled. Yes it makes it more vulnerable adding more devices but for me thats not a critical function.
I recommend to set up the variables on your charger/load so they always can work without it and in case of issues the rules kick in and shut down :slight_smile:

well not really i mean this is not what the issue was about however that would be nice as well and yes i agree that should happen over modbus or can, maybe we will get that in the new controller.

My issue is to have a double mechanism. For example, when should the main breaker trip ? I would like one more set of the under/over voltage rules with other voltages set that will trip the CB because that should be last resort if something goes waywire and in that case i trip the CB and i have to activate manually.

Ok @donnib then im not following and i feel a bit dumb :stuck_out_tongue:

But lets say you have 2 rues for overvoltage on cell level. What would
Rule 1 do?
Rule 2 do?

So i can understand what those 2 rules would do in your case

Hi gentleman, do you encounter this kind of component shortage problem? Mine since January for D1 component through JLCPCB and LCSC. Any solution or optional other component recommended would be appreciate. Thanks.

Rule 1: switch charger to float or disable charger until rule resets
Rule 2: trip the circuit breaker

In other words if Rule 1 fails e.g the voltage raises further to Rule 2 level then something went wrong with the inverter since it keeps on charging even though we told it not to so we activate Rule 2 meaning we pull the plug.

Does it make more sense now ?

See this

It does. But for me you should either set the values better on the Charger so you dont need it or it should be a limit function. :slight_smile: Based general how bms systems work.

gracias

Thanks for info.

Maybe someone can help me with avrdude. I’ve got avrdude installed and I’ve copied the new avrdude.conf file from stuart’s link. But there is no part t841 in it. There is t84, but not 841.

Are you using the latest BOM and v4.40 design?

I’m just discover the new version of circuit after watch your youtube vid. Sorry my bad.

Anyway, thanks mr stuart for the great design you’ve made, appreciate most.

Yes that’s fine, are you ordering the v4.40 boards?

yes . JCBPCB has sender the boards today I thin at the end of the week are in Malaga. An 10 New controller arrived after tomorrow ( now in France) for the spanish team.

Thank you so much for sharing your knowledge and experience, I have integrated diy bms into home assistant, but the parameter cell range is not published. It’s very strange.

dowdload *.h ?

A lot of the parameters can be calculated outside of diyBMS, thats why I didn’t publish everything - to work out the range you just need to find the max and min of the cell voltages

You don’t need to download anything - please follow the instructions on the GITHUB page on how to flash the firmware to the ESP32

I had the bms slaves more than a year before i found my leaf cells so i was not able to get the specific leaf bms boards, in case you are in the same boat i made these brackets:

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