DIYBMS v4

[Robert.Wall]

If there is one moving contact, which makes one contact path when the relay is energised and a different contact path when the relay is not energised, then:

The moving contact is called “common”,
The contact which is open when the relay is not energised is called the “normally open” or N/O contact,
The contact which is closed when the relay is not energised is called the “normally closed” or N/C contact.
Together the common and N/O contact are the N/O pair of contacts, the common and N/C contact are called the N/C pair.
The “normal” state is when the relay is not energised.

[stuart]

The prototype PCB design for the new controller arrived today, this is a “dry fit” of parts in the DIN rail enclosure. Looks like it all fits!

[atanisoft (Mike Dunston)]

Which ESP module is that? Will it work with the ESP32 DevKit-C?

[stuart]

@atanisoft

Will it work with the ESP32 DevKit-C?

Yes - it is a DevKit-C, but with external antenna socket.

[lanzecki (Simon)]

Tell us more Stuart?

[stuart]

See this post…

[DIYBMS Announcements - #7 by stuart]

[Alex_Dr_Lange]

Hi!
Is it also possible to export the cell voltage range via mqtt? I’ve got all my voltages in emoncms, but somehow emoncms is lacking the post processing features to recalculate this, or I’m just too dumb to do it…
thank you!

[stuart]

@Alex_Dr_Lange

Is it also possible to export the cell voltage range via mqtt?

At present the web pages calculate the voltage range, rather than the controller, so isn’t available for MQTT to transmit.

I’m currently moving this calculation to the controller as part of a major code change/improvement but not yet released.

[Alex_Dr_Lange]

OK thank you. As I already have to use a python MQTT translator (can’t directly use MQTT with my emoncms, have to use HTTP upload…), I’ll just add some recalculations to my python script for now. That should do the trick.
Otherwise really great BMS and software design TBH!

[donnib]

@stuart does the MQTT also receive messages to control the relays ? I mean if i have some other rules in a separate HW can i tell diyBMS using MQTT to activate one of the relays ?

[stuart]

@donnib

can i tell diyBMS using MQTT to activate one of the relays ?

It doesn’t support this at the moment, it may be possible after the move to the new ESP32 controller, the existing ESP8266 is running a bit low on power to handle all these different interfaces.

[donnib]

@stuart That would be nice, any progress on the shunt or are you mostly busy with the new design of the diyBMS you posted earlier ?

[stuart]

I’m still looking at the shunt, the problem is getting that to communicate back to the controller the ESP8266 just doesn’t have enough I/O pins left for me to use, hence the new controller.

[donnib]

Ahh now I understand why you started working on this. Nice. Let us know when we can order the new PCB for the new controller while you work on the software.

[fruehwi (Tom)]

Hi all, I’m new here and would like to order from JLCPCB, but unfortunately are the D1 “TL432G-A-AE3-R” not in stock.
What is a the type of D1 what I can use for my order.

Thanks for support.
Best regards, Tom

[chmistry (Arie van Dobben)]

Best is to wait because the one replacement item is also not in stock.

See this post where the issue is also addressed:

DIYBMS v4

@gazzaman2k as @GeorgeBoudreau mentioned he is using the AZ432 chip which is the same design as the v4.21 boards on the LEAF version. AZ432ANTR-E1 = VOLTAGE REFERENCES 1.25V 18V ±0.5% 20PPM/°C SOT-23(SOT-23-3) ROHS This part is currently out of stock on JLCPCB, a similar part is this. TL432G-A-AE3-R = VOLTAGE REFERENCES 1.25V 15V 50PPM/°C SOT-23(SOT-23-3) ROHS It should be a drop in replacement. There are other components that would work, but these are much more expensive.

[WanderingZanzey]

Hello, new to the diyBMS. I was wondering, exactly what data is sent over MQTT?

My setup: Raspberrypi 3B+ running mosquitto broker, apache webpage, phpmyadmin, sql, and node-red.

I have successfully displayed my node-red workflow on the webpage and connected the UI to the mqtt broker.

Now, my question is - what kind of data will i be getting? I’ve tested the setup with mosquitto_pub from SSH and node and the webpage both respond.

I am just not sure exactly what msg.payload i am capable of parsing. Can we do msg.temp or msg.mV for example under the diybms topic?

Would love some help with this

[fhorst1 (Frank van der Horst)]

@stuart,

The new controler board…
It have now 2x relays?
If possible to control 4 that would be great.
It’s something I really do use.
Temperature turns on fans.
Naturally too high to stop charge, too low to stop discharge and one to disconnect the battery in case of emergency.

The J1 is used by my smoke detector who have besides audio signal also a relay, who triggers J1.

Fire is for me a case of emergency
So is a cell dropping below 2.3v
.
Some others like mushroom stop button also counts as emergency.

I don’t really need to move towards new version of controller board (yet), it’s to inform you that several of the options are indeed used!!

If they are lost in a new version, it would stop me from upgrading.

[fhorst1 (Frank van der Horst)]

I’m confused here.

The controller board receive power from USB, yes?

Why would additional power source be needed?

The relay board doesn’t seem to need external power.

Probably stupid question, still in the process of building the Powerwall.

After 6 days I’m ready to build the second layer.

Due to medical reasons I’m not the fastest builder .

Lucky our inverters (Revo II from Sorotec) can work without batteries.

We have power between 09.00 and 16.00

When the 50 kWh LiFePO4 Powerwall is really, it’s 24/7

I wrote how the relays are being to be used,
I simply bought DC to USB, it works between 9 to 30v.
2 in series provide me with 8 ports, also to be used for Ammeter and stuff.

They are about 4 USD, include transport to Thailand

Does the controller board needs additional power source?
Or just the usb on the WiFi?