SIMP BMS with BMW Mini Electric battery.

[DFDF]

Hello everyone,

I'm new to the forum and really appreciate anyone's help.

My end goal is to use a mini electric battery in a classic car conversion. I came across SIMP BMS and it seems like a great solution for an open source BMS. I have the battery and the BMS which is loaded with the BMW I3 firmware. Obviously the Mini electric battery firmware is not directly supported, but my logic is that the CSC's are the same so it might be possible.

I have it all set up and I have connected to the batteries "master connector" I defiantly have communication with the battery, it actually seems happy and is reporting as ready to run. However something is wrong. It is showing all 12 CSC modules, with cells 0-11 on each module, but cells 8-11 are showing as 0V on each module with cells 0-7 showing exactly the voltage i would expect at around 3.8v.

Further to this from modules 9-12 every cell is showing as 0v. Only 64 cells are showing in the debug screen and it doesn't seem to matter what I set the cell series to, it only ever shows 64 cells present which is consistent with cells 0-7 on modules 1-8 being present.

The BMW I3 battery is made up from 8 CSC modules with 12 cells in each. Where as the Mini electric is setup also most the reverse with 12 CSC modules and 8 cells per module. I'm thinking this is probably the reason. My thoughts.... which are only thoughts I do not know, are that there are 4 wasted addresses in modules 1-8 as cells 8-12 are not present, when we get to module 9 we are out off addresses so from there on they are 0.

I'm wondering if the fix could be altering some of the code from the BMSModule.cpp, I can see there is a loop looking for 12 values, this might just be the start of the fix.

Can @Tom91 or anyone tell me if I am heading in the right direction or am i going off at a tangent?

Thanks in advance for any help.

[tom91]

You need to expand the code base and add the 4 missing commands for the CMUs. Then you can also clean up to only register/look for 8 cells per CMU.

UpdateJust check my code base, guess you are in luck you just need to set it to MineE CSC spec, in the battery settings menu.

https://github.com/Tom-evnut/BMWI3BMS/b ... .ino#L3329

[DFDF]

That's amazing thanks Tom, this looks like a newer firmware than what the board was shipped with. I will give this a go Tuesday.
Thank you for your help.

[tom91]

board was shipped with

Where did you get your SimpBMS from and when?

[DFDF]

Hi Tom,

No I'm wrong, it shipped with the latest firmware, I did as you said, set the cells to 96 and its all working perfectly.
Thank you again for all your help.

[tom91]

Where did you get your SimpBMS from and when?