Hymotion CAN messages

Hi all, I have a Hymotion on my car since over 130 000km. I have fully cycled it just shy of 3000 times!

The system is still running strong but I do notice a loss in capacity (that is to be expected with such a well used pack!). Also, the pack stops working when the spoofed SOC is at "3 bars". It used to go down to 2 and even 1 bar in the first year. I am just wondering if the pack cuts out because of a single low cell voltage or is it generalized. I did have in the past an Excel sheet with all the Hymotion CANbus messages and there was a max/min cell voltage in those. Somehow I have managed to loose it...

Would anyone have the CAN messaging of the hymotion system?

Thanks all for your help!

 

While we are at it, there is a DB9 connector comming out of the HyMotion pack. I would guess it is a CANbus port, but it might also be a serial port. There is probably a diagnostics software for those packs. Anyone has some info on this topic?

 

Ok, I have re-figured out the CAN messages and was able to make myself a little display. I watched the numbers today on my commute.

I see that I have at leat 1 cell that is weak, but since I can just read the highest and lowest cell, I have no idea of the distribution. Anyone know how to poll the hymotion BMS? There must be a way to get it to spit out much more info...

The pack cuts out at 27% SOC, with one cell dropping bellow 2.50V under load, while the highest cell is still above 3V. See attached picture (taken about 1 minute after the pack capitulation).

I would like to point out that once fully charged all cells where very close to 3.5V, so no terminal imbalance situation here...

Anyone has ever opened one of those Hymotion packs? I wonder how hard it is to replace a cell...

 

Fantastic info, thanks alot planetaire!

From what I see, it is not an easy job to replace a module... I still need to figure out how to read individual cell voltages either over CAN or on the exposed DB9 connector next to the pack (that is probably a CAN plug also...).

Merci et bonne journée!