So I was wondering if anyone was interested in trying to get this to work? That is trying to get the Batrium Shunt Mon to communicate to the DIYBMS Controller. I myself do not know enough on how to do it but know enough that it can be done. I have just purchased the V4.61 Controller with the shunt already on it but didn’t read till later that it is limited to 85v. I started this project of mine because I wanted a cheap solution for a BMI/BMS for a 96s Lifepo4… I have since decided to go to a 36s instead but it is still over the threshold for the shunt. I have been looking around for a few weeks for a cheap solution and it was under my noise the whole time… For just $120 USD we can get the Shunt Mon, HV reading is 0-600VDC. Now the next steps… Anyone else interested?
there is a guy that changed the code to use a voltage divider, he is using 120v 32s i think.
It would be a great feature for the main project.
I thought I saw a post that Stuart replied to and I thought he said that a voltage divider wouldn’t work accurately with the existing shunt that’s on the board.
After a few google searches (“Is a voltage divider circuit linear?”, “Does a voltage divider circuit need temperature composition?”) I’m now a little worried about Temp compensation and drift. I’m just not sure if it is even necessary for me to even worry about. I just want my Coulomb count to be accurate.
Thanks for the reply
Thanks for posting this. I did see this before deciding to post. I do see that it is currently being tested. It would also be great if Stuart would perhaps implement this, it would prove it to be rock solid to use.
Thoughts---- I mainly figured that the Shunt Mon is an off the shelf product that anyone could just buy and with a download and a firmware update they could maybe use. I was just thinking that it would be easy to take the information from the Shunt and program the DiY controller to use the received messages. Maybe its not so easy?!? I really don’t know as I can only copy and past code on an Arduino at the moment.
Current monitor shunt communication via CANBUS instead of RS485.
I wonder if the controller would be able to communicate CAN data with a stand alone current shunt? Isabellen Hutte is a stand alone current shunt monitor capable of measuring voltage up to 1000 DCV and over 500A. It only communicates via CANBUS. Using such a shunt would rezolve the voltage limitation of 85DCV and increase the capability of DIYBMS.
My understanding is that the controller sends data to Victron CERBO via CANBUS but I doubt that it can also receive CANBUS data.
The answer is yes but there is more to just reading and writing over the communication line. My question would be is if the canbus is isolated on that module or not?
You mean the Isabellen Hutte shunt being isolated? Don’t know, but I would say that we should be able to find out. On the Openinverter forum, there are a few people who are using this current shunt monitor for their EV conversion. This is my intention as well, to use it for my EV conversion. If we can make this shunt communicate via CAN with DIYBMS, would be great. Alternatively, the Batrium shunt (650DCV / 500A)would suit my project as well. Yesterday, I have asked Batrium if their shunt uses RS485. They haven’t yet replied. It uses serial communication, but other than that I don’t know. Doing a bit of search online, I found out that there is hardware capable of “translating” CAN messages to RS485 and vice-versa. Search for CAN485 and you will find one product from sparkfun, one from a chinese manufacturer, Lilygo and another one from 3onedata(chinese as well). If I understood correctly, we should be able to use this hardware to convert the CAN messages from the shunt into RS485 which will then be read by the controller. This is all I know so far. If Stuart would have some time, maybe he can let us know his opinion.