openinverter forum

Bratitude wrote: ↑Fri Oct 23, 2020 4:30 am in theory it should be possible to add a additional gen1 volt slave onto the Chevy volt bms train? Or is the teensy 3.2 almost out of address space at this point?

I’d like to possibly add an additional cell group to the pack, increasing storage and voltage without paralleling two full packs.

mdrobnak wrote: ↑Fri Oct 23, 2020 6:50 am

Bratitude wrote: ↑Fri Oct 23, 2020 4:30 am in theory it should be possible to add a additional gen1 volt slave onto the Chevy volt bms train? Or is the teensy 3.2 almost out of address space at this point?

I’d like to possibly add an additional cell group to the pack, increasing storage and voltage without paralleling two full packs.

It's not an issue of the Teensy - you'll hit into CAN address collisions as they are fixed IDs as I understand it. (I've yet to wire mine up )
The Teensy is certainly powerful enough for the tasks assigned to it.

-Matt

tom91 wrote: ↑Fri Oct 23, 2020 9:24 am

mdrobnak wrote: ↑Fri Oct 23, 2020 6:50 am

Bratitude wrote: ↑Fri Oct 23, 2020 4:30 am in theory it should be possible to add a additional gen1 volt slave onto the Chevy volt bms train? Or is the teensy 3.2 almost out of address space at this point?

I’d like to possibly add an additional cell group to the pack, increasing storage and voltage without paralleling two full packs.

It's not an issue of the Teensy - you'll hit into CAN address collisions as they are fixed IDs as I understand it. (I've yet to wire mine up )
The Teensy is certainly powerful enough for the tasks assigned to it.

-Matt

Correct, nearly all OEM Canbus systems have fixed IDs, or atleast a fixed number for IDs you can assign (BMW).

So usually this would mean you are limited to a MAX amount of slaves in the original pack, you can always run less if you want.

Bratitude wrote: ↑Fri Oct 23, 2020 4:30 am in theory it should be possible to add a additional gen1 volt slave onto the Chevy volt bms train? Or is the teensy 3.2 almost out of address space at this point?

I’d like to possibly add an additional cell group to the pack, increasing storage and voltage without paralleling two full packs.

Bratitude wrote: ↑Fri Oct 23, 2020 10:57 am

tom91 wrote: ↑Fri Oct 23, 2020 9:24 am

mdrobnak wrote: ↑Fri Oct 23, 2020 6:50 am

It's not an issue of the Teensy - you'll hit into CAN address collisions as they are fixed IDs as I understand it. (I've yet to wire mine up )
The Teensy is certainly powerful enough for the tasks assigned to it.

-Matt

Correct, nearly all OEM Canbus systems have fixed IDs, or atleast a fixed number for IDs you can assign (BMW).

So usually this would mean you are limited to a MAX amount of slaves in the original pack, you can always run less if you want.

right, of course. in that case I’d run a second teensy with the additional cell group in series to the pack.

bexander wrote: ↑Fri Oct 23, 2020 3:25 pm

Bratitude wrote: ↑Fri Oct 23, 2020 10:57 am

tom91 wrote: ↑Fri Oct 23, 2020 9:24 am

Correct, nearly all OEM Canbus systems have fixed IDs, or atleast a fixed number for IDs you can assign (BMW).

So usually this would mean you are limited to a MAX amount of slaves in the original pack, you can always run less if you want.

right, of course. in that case I’d run a second teensy with the additional cell group in series to the pack.

May I suggest that the use of an extra CAN-controller+tranceiver should do the trick. No need for an extra micro controller.

tom91 wrote: ↑Fri Oct 23, 2020 5:04 pm

bexander wrote: ↑Fri Oct 23, 2020 3:25 pm

Bratitude wrote: ↑Fri Oct 23, 2020 10:57 am

right, of course. in that case I’d run a second teensy with the additional cell group in series to the pack.

May I suggest that the use of an extra CAN-controller+tranceiver should do the trick. No need for an extra micro controller.

If you want to re write the code to do this, feel free to do so.

bexander wrote: ↑Sat Oct 24, 2020 4:46 am
Reading my post above again I realize that it did not come out right.
I do not have the knowledge to re write the code. I was only trying to suggest that it could be done with another CAN-controller but the firmware have to be adjusted accordingly.
I think what is done here is great, but even so, it can be improved further.

mdrobnak wrote: ↑Mon Nov 09, 2020 10:15 pm I noticed in Dusty4's output the same thing I see - 0V for middle cells...Is this a known issue? And is it simply ignored by the ignore cell with voltage less than threshold setting?

Dusty4 wrote: ↑Sat Nov 14, 2020 11:06 am Hey Tom, I've got it hooked up again and inputs work correctly now . I've got a problem with the tc charger I'm using, the bms is in charge mode, plug in the charger and I get red,green,red led (bad communication). I see in the serial terminal the expansion module is set to 500kbps (I'm unable to change it) and the charger has the option of 250kbps or 500kbps. I'm not sure what the charger would be set at, and I got very little documentation with it. What is your thought?