yes, i don’t need the parts anymore
pm send
Here’s a tip if you choose to hand solder your boards:
Using solder paste, heat up the boards first, then quickly dab the solder where you want it. Once the boards cool down, you can place your components where they go. (They kind of stick in place)
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HI.
Version 4.4 is very cool.
But for Version 4.41 I have a request for enhancement.
The power plug you use is still PH2.0 but the balance power increased.
Even with the 4.21 modules doing less current we see a big voltage drop on balancing, with higher current now it will be even bigger.
A XH Connector for example (with 2.5 mm pin distance) can be equipped with much thicker cables and will fit for the current better.
Or a solution with 4 holes (for both plugs ph 2.0 and xh 2.5) will also work I think.
Are you running the latest code? The latest code provides a much more stable voltage reading when balancing is running.
What cells are you using? Maybe my design for 272Ah lishen cells is also sutible for you:
They have an balancing current of 2.6A
We are a large group of people in Spain who are making our own batteries with prismatic cells LISHEN272 and CATL 310.
We loved your Fork, I even tried to order one in Jclpcb but I found a lack of supply of some component, the resistors I think.
I will upload to the telegram that we use your link. and what has been said if you would like to share the gerber and the bom, etc. It would be great to order some to try.
I still have a little doubt about the separation between terminals of the CATL 310 I am behind the Chinese who are going to supply them to us to have exact measurements.
We are in touch .
Fabien, another thing that we comment is that it would be great to make a plate only with the battery terminals and connection to the V4.21 modules that we already have many of us, it would be a plate in which a V4.21 module is connected with two pins its connections to battery with a plate that is placed on the Lishen. It is a way to reuse the modules you already have for prismatic cels. I made a sketch.
Hi George, nice job!! Where can I find wiring diagram of 2 and 4 jst connectors? I’ve been trying to make modules work without success, I would like to double check I’m connecting all properly. Just tested the controller with standard modules and worked out. Thanks in advance
I have been using the 2.5mm for awhile, along with 18 AWG wire. and trim the crimp tabs down with my side cutters, before i solder the wire to the little header pin inserts
Late last year I ordered, built and programmed some boards, including 5 control boards. All 5 five of them report “PCF8574 is NOT connected/fitted, relay control not possible”. I looked for obvious solder problems, but JLC did them and they look fine. Since we have 6 of the Wemos D1 minis, I programmed a fresh one for each controller board, so there’s no obvious thing to diagnose there either. Any suggestions on further things to investigate would be very much appreciated since we have no working controllers. Thanks!
—edit—
Not sure how I didn’t see the previous comments about the i2c address last time I searched this. I pulled the latest code and went looking to change the address, but it seems like now both addresses are specified. It’s not clear if there’s still a change to be made. So…erased and programmed the board again and it still doesn’t work but the error message is now:
“External I/O interface is NOT connected, relay control not possible!”
Terminal says:
“…
PCF8574 at address 0x20
PCF8574 not fitted
…”
Then it outputs Error State=4 every few seconds.
Have you updated to the latest code?
If not give that a try. The PCF chip has different addresses, and jlc seem to use random ones!
The latest code, searches for the chip on multiple addresses.
Ooh yeah, was just updating my reply with the results. Still weirdness.
—edit—
So as mentioned in the last edit, I did try updating software. It settles on 0x20 and then says “not fitted”.
The chips are super hard to read, but it seems to be a PCF8574T. I looked up the datasheet, but nothing in that helped me understand what address to use.
New boards look great! Can’t wait to get some and starting testing them out.
I notice that using the bom from JLC for the latest v4.40 module the resistors are 1/3W rather than 3/4W discussed above, guessing these been selected because of JLC availability, but will be at the limit when at 4.2V?
Also looks like they are now very low on stock of the 1% too, they have lots of 5% available, assume this could make the issue above worse so best to wait until they restock.
@stuart since you’re redesigning the controller board based on ESP32, would you consider adding some A/D, either the native ESP32 or a separate IC? This would facilitate reading from current shunts for input and output current.
UPDATE: I just ran across your Jan 2021 video, at the end you mentioned a current shunt board with RS485 communication capability. So I assume that facilitates current monitoring. Can I have two, one each for input and output current? Also, will the software someday do state of charge?
Is the controller software capable of driving a latching relay (by sending a pulse to control it)?
Thanks @stuart for all your great work!
Yes to both of those, but the current monitor has not yet been released/finished!
Yes, pulse output is possible - I don’t think its been tested much though
If anybody needs a guide how to do diyBMS → MQTT → NodeRed → Influx 2.0 → Grafana i made one here in the wiki Visualize data from the diyBMS · stuartpittaway/diyBMSv4 Wiki · GitHub
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Nice!
The ADC on the ESP32 is very noisy and I would recommend an external IC that takes care of that work, something along the lines of an INA237 (85V max voltage) or INA233 (36V max input) which are both I2C connected.
The ESP32 ADC can be worked with if you take multiple samples and average them, it may also help to add a capacitor on the input pin to smooth out spikes. Keep in mind that it is also limited to only six pins while WiFi is active (32,33,34,35,36,39). The ESP32-S2 or even the yet to be released ESP32-S3 will have more ADC pins available but I have not yet tested the ADC to determine how noisy it is yet.