Current Shunt Add-On Board [DIYBMS]

[@nebulight]

I don’t think you get enough credit for the great work you are doing. Bravo!!

[@StuartPittaway]

Appreciate that

[@atanisoftware]

Question on powering the controller, I'm currently powering it via a USB port on the inverter that is powered from the battery. Do you think this will still be suitable if I upgraded from external shunt to on-board?

[@StuartPittaway]

Difficult to know for sure in this scenario Mike.

[@andrewbowden1076]

@StuartPittaway Just purchased the 4.61 Controller was planning on using it with a 96s Lifepo4 system. I just watched this video and reading the comments, I thought the controller wasn't limited by voltage but in away it is because the shunt is only capable of 85v.. I'm not sure what to do now, I thought this BMS was my solution.. Is there a way that I can incorporate something like the VISHAY HV-IBSS-USB shunt? This thing is pretty awesome, up to 850v.

[@kodl1969]

great work!!! I have two INA229...

[@StuartPittaway]

Nice!

[@anthonyevans7911]

Stuart, have you got any of these add on boards left by any chance, populated nd built or bare board. Id gladly buy one to complete an v4.2 controller fella.

[@sjdtmv]

Thanks greatly Stuart for you great knowledge and assistance.

[@yancymuu4977]

Have been using your ina229 current monitor on my new solar system for about a week, modified with 3 current sensors. I note a low frequency oscillation of several 10's of an amp with a period of several minutes. At night when battery current should equal load current, the oscillations get out of phase where sometimes load current goes up while battery current goes down etc.. Problem is difficult to analyze with scope because of huge amount of high frequency noise. I am thinking a possible cause may be the high inductance of my inverter coupled with the 1 uf filter capacitor on the input of ina circuit. I changed the adc_config register to collect 1024 sampled (from default 128 to 1024 --- 0xffd4 to 0xffd7) and this helped the problem quite a bit. Will work on it some more. Thanks for inventing such a great circuit! Hope this is interesting.

[@StuartPittaway]

Thank you for the information

[@bertv602]

Great work! Now wait until mouser has stock on this item. Difficult 🙂 If there is someone willing to share an order (Belgium), PM me.

[@StuartPittaway]

Order directly from TI, they ship worldwide

[@republicofvegans712]

Can we attach different shunts to the controller? I.e. ones that support more than 85 volts?

[@StuartPittaway]

The shunt is a current monitor, the voltage the voltage doesn't matter. However the INA chip I use has a maximum of 85V voltage reading

[@Demaflickers]

Hi.. Thank for great work! Have a question, want to use this for EV conversion, 110series...does it mean I will require 110 modules?

[@StuartPittaway]

Yes, it would. With a high voltage DC setup, I would look for a specific EV BMS. Especially as it's safety critical

[@Demaflickers]

Think I'll go ahead with Orin bms, or reverse engineer a Nissan leaf bms I have lying around

[@yuanianlin]

Thank you for sharing ! I 'm a novice, the display shows ' The controller is having difficulty communicating with the cell monitoring modules. ' What does it mean, the page also has no data, the control board has no problem, the monitoring board uses 440, how to solve

[@StuartPittaway]

Generally means a problem with the cables between the controller and modules.

[@yuanianlin]

Thank you for your response ! But I 'm sorry, it still doesn 't work.

[@yuanianlin]

I like your BMS very much, I want to continue, can you tell me the specific information of the cable using BMS, there may be a problem in this regard

[@StuartPittaway]

@@yuanianlin open a GitHub issue for the problem, it's easier to talk there

[@MenoCore0815]

Hi Stuart, really great work and effort you're spending so many years now. Thanks for that! I wanted to upgrade my esp8266 controller to esp32 because of the shunt option - I chose the add on board and now I got stuck with 0-readings. Perhaps you can give me one or two hints? As I populated 2 controller boards (v4.6) and 3 add on boards already, I would exclude a soldering issue with the INA229 chip.

[@StuartPittaway]

Hi, probably easier to open a GitHub issue, it's difficult to support via KZbin messages

[@TheDivemaster88]

Hi Stuart, great work again. just ordered the "old" board 5 days ago... you know, if it is possible to use the ina 229 also on the original version of your shunt system?

[@StuartPittaway]

The original shunt can only use the 228 chip - not the 229.

[@jasondevine6014]

Awesome.. having a shunt is invaluable. I am lucky to have sourced some chips before all the shortage, however love the idea of a all in one. Just need wifi ap mode now so that it can work in a caravan easily.

[@StuartPittaway]

That's a great idea! Must get around to that ticket!!

[@dittagecoeco2738]

Great work. Can't wait to build all the diybms, now including a shunt!

[@StuartPittaway]

Go for it!

[@PaulSturbo]

Hi Stuart, great work you are doing on this, much appreciated. Your comment on ground isolation has stuck in my mind. I'm now trying to get the BMS to Sofar inverter CAN working again after I did that initial testing of the Pylontech emulation last year. You probably remember that I had ground isolation problem which I solved using a mains powered ground isolated supply. I'm now powering the BMS of the battery as suggested but am getting the ID05 error again when I reconnect the battery. Can you advise which buck converter you use? Mine seems to be causing a problem. Thanks in advance.

[@StuartPittaway]

Remove the ground connection from the CANBUS cable, just use canh and canl connections

[@PaulSturbo]

@@StuartPittaway Thanks. There isn't a ground wire on the CAN cable. The problem appears to be that the ground plane of the HYD inverter is at PV voltage, in my case 215v relative to Battery negative. Supply at the BMS needs to be ground insulated and anything connected to the BMS also needs to be isolated from ground.

[@yancymuu4977]

Want to thank you for your current monitor design. I created a somewhat expanded stand alone ina229/esp32 board with 3 current monitors channels based almost entirely on your board, and software. Also added a mod-bus interface for status and control of my Epever charge controller. Just got the board working, but still digesting the software. I wanted to monitor battery, load, and charge controller current simultaneously. I used Easyeda for the board design, with a somewhat different esp32 module. It was very challenging soldering the ina229 chip, but my wife managed it with her steadier hands. I have had good luck exporting data with MQTT and displaying with node-red. Thanks again.

[@StuartPittaway]

Excellent, glad you found it useful

[@yancymuu4977]

@@StuartPittaway thanks. Now trying to get it tested, and having trouble getting the current to agree with my test setup. With the calibration register set to the value per online tool, I am getting about 5% low, and the negative current doesn't quite agree with the positive. Can always change cal value, but not comfortable with that. Now building a second channel to see if results are the same. I have a .72 milli-ohm shunt, and have set max current to 40.96 amps.

[@anthonyevans7911]

Brill Stuart. Just to clarify, the new controller version 4.6 will have the current shunt integrated? Reason I ask is i need another 2 controllers and 3 current shunts at the moment for new installs, need building them as soon as possible really buddy. Thanks, and great work.

[@StuartPittaway]

Yes integrated into the controller

[@anthonyevans7911]

@@StuartPittaway If you want to pass oe of your shunts on to a few patreons to test, i`m available if your want to. Thanks

[@rubenfernandez4070]

Awesome work. Placing a voltage divider. Could the INA229 VBus reading voltage be increased for high voltage systems? For example for reading 150Vbatt

[@StuartPittaway]

I doubt that would work, outside the specification of the INA chip.

[@CollinBaillie]

​@@StuartPittaway What about using a voltage divider though? Bring that down to spec for the INA229... It would need a software change to accommodate such setups. Some sort of multiplier ratio the user would have to supply.

[@StuartPittaway]

@@CollinBaillie all the internal calculation inside the INA chip would be wrong as well, the chip does all the columb counting

[@r2db]

All these current monitors work by measuring a differential voltage across the shunt resistor, which itself is a very accurate resistor of a known value. If using your example you divide the battery voltage by 10 to get 15V then your current measurements will also be off by a factor of 10, and any variation in the resistor dividers would add further inaccuracy to the readings. You would need to do some custom modification of the firmware to compute the correct values but still be left with potentially variable errors from the voltage dividers.

[@justinc.8191]

Lovely video, can't wait to see more

[@StuartPittaway]

More to come!

[@chapulino1000]

Great Stuart . happy to be one of your patreons.

[@StuartPittaway]

Much appreciated!

[@chapulino1000]

a doubt Stuart. What distance could there be between the controller and the resistor (shunt) consider a distance limit or we could have a meter or a meter and a half of distance, will it greatly affect the reading precision or interference?

[@StuartPittaway]

I've tried about half a metre worked fine, you'd have to try it!

[@herrcbaer4429]

Just drill the cable and use a bigger diameter 1,5mm2 or 2,5mm2

[@tobimai4843]

There is practically no current flowing so distance is not that important. You probably get some noise in it in longer cables but the digital INA ICs have some built-in filtering/averaging

[@PlexMulti]

You are doing well!

[@StuartPittaway]

Thank you

[@Whereswally606]

sorry to spam your most recent video, I am struggling to get any slave 4.21 boards firmware uploaded EDIT my new usbasp device arrived. same problem as before observed. tried -F upload flag, tried -B16 upload flag. all to no avail. Any advices here Stuart. Last thing to try might be the tinyisp like Adam Welch does but honestly think that the slaves may be broken too. I struggled last night to flash the 4.21 slaves Uploading .pio\build\V421\module_fw_V421_attiny841_421_eF4_hD6_l62.hex avrdude: error: program enable: target doesn’t answer. 1 avrdude: initialization failed, rc=-1 Double check connections and try again, or use -F to override this check. any chance to send one to you to rule out that its not my equipment letting me down?

[@StuartPittaway]

You can try the tinyISP but I'm starting to wonder if the boards are no good/bad soldering or faulty ATTINY chips.

[@Whereswally606]

@@StuartPittaway yep me too

[@Whereswally606]

Might try cleaning the flux off the boards from my soldering but the soldering was pretty tidy

[@Whereswally606]

I do get a green flash on the board when it tries to flash

[@StuartPittaway]

Do you have an Arduino which you can program using the usbasp adaptor? Straight from the Arduino IDE

[@chuxxsss]

Morning Stuart, from sunny Australia. Never did get them boards working.

[@anthonyevans7911]

Gday mate... i`m relatively new into the DIYbms and will say it works very well, and now also works well in canbus mode simulated as a pylontech battery, works well with my Solis RHI 5k hybrid inverter. My previous build was with a Zeva BMS, awesome bms to be fair, built there in Oz, but he doesnt do them anymore.

[@chuxxsss]

@Anthony Evans I have 5 boards here, half populated, I live in Victoria.

[@anthonyevans7911]

@@chuxxsss Hi again, what version controller boards are they?

[@chuxxsss]

@@anthonyevans7911 4.0 or 4.1

[@anthonyevans7911]

@@chuxxsss ok, not the one with the esp controller and screen