[GreenTecAuto]

I think this may be what you wanted.
The smart car was made in 2011, where as the Rav4 in 2014.
That could explain why the smart car bms is different and why the Rav4 is similar to the model s.
The rav4 also has 4 smaller 5 cell modules that have the same board but with one less row of balance resistors. Everything else looks the same.

 

[Tomdb]

The Smart BMS must have some more chips on it, besides the main micro.
As that micro is not a BMS specific one so cannot sense the voltage ranges required.

 

[GreenTecAuto]

There are 15 of these.
bb ina 148ua 09yyq
http://www.tij.co.jp/jp/lit/ds/symlink/ina148.pdf
Nothing on the back really.

 

[Tomdb]

So the Tesla BMS used in the Smart car will be hard to crack, as you most likely need a working pack to decode it.

However any bmses derived from what i believe the roadster architecture is, so Rav4 Merc B cell and Tesla Model s/x is relatively straight forward.

 

[Ocean]

So the Tesla BMS used in the Smart car will be hard to crack, as you most likely need a working pack to decode it.

However any bmses derived from what i believe the roadster architecture is, so Rav4 Merc B cell and Tesla Model s/x is relatively straight forward.

Hello,

I'm very interested. I live off-grid and my House Batteries are Tesla Mercedes B-Class Hybrid 7S Modules. I have three of them in parallel for about 9kWh (24v system). Been running these for about 2 years now and it would be nice to balance them.

The Slave BMS boards are on the modules, but I've left them disconnected. I would love to have them operational. Even if I had ONE of your controllers, I could switch it between my three modules just to balance the cells... although I believe they are functioning well, it would be nice for the long term.

I'm interested in learning Arduino but I have no experience. I'm handy... but again really a beginner with Arduino.

Are there any of these available? Or could you give me some very straight forward step-by-step??? It's really exciting what you're doing.

BTW for everyone watching this: For some reason the leads on my Tesla 7s modules (the wires running from the cell blocks to the BMS Board) have failed at the weld points. I was taking comparative measurement and they were all over the place. I thought... what??? Because the modules are working fine. Looking closer I found the balance wires to be loose at their weld points. So be sure to look into this and make sure your BMS leads are solid at their connecting points on the Cell Blocks.

Cheers!

 

[kennybobby]

I have a few Tesla bms from the Rav4 ev (6cell) and at least one from the Smart car ev (15cell).
Is there any interest in taking a crack at those? You know, for science!
There are plenty of those out there as well.

i'm willing to trace out the circuits and draw up a schematic, for science of course! It's always good to see the different ways that the OEMs use to read voltage and turn on balancing, etc. Sometimes we get lucky and can extract the code and learn how to modify it to suit our purposes, e.g. http://www.diyelectriccar.com/forums/showthread.php?t=89470

 

[GreenTecAuto]

Better than sitting and collecting dust.
PM me your location.

 

[Tomdb]

Currently running the pack attached to victron charger/inverter to cycle it.

Looks like she is balancing out pretty nicely.

As the pack is a 12S conversion, the temperature sensors are only on one of the two slaves. Need to remove Collins pack status or correct it so it does not fault out.

Okay so my pack overshot on the SOC calc, reason:
On boot up it uses a simple look up to roughly guess the SOC

4.2V is 100% 3.1V is 0%, so that lower value needs moving down. However the slave boards are keeping the cells nice and balanced during the charge of 35Amps and during the absorption phase allowing the slightly lower ones to catch up.

 

[Kevin Sharpe]

Looks like she is balancing out pretty nicely.

Very nice... just need to get this talking to Damien's Tesla charger controller

 

[Tomdb]

Turns out I was just balancing with a inferior algorithm.

Balance cell if above balance setpoint.

This ofcourse wont do, should have changed it. But who looks at the full charge performance when there are other issues to address first.

Will become : Balance cell if above Lowest cell voltage.

Kevin, I got a sneaking suspicion it will talk very nicely.

 

[CarelHassink]

Hello All,

Can I ask in this thread some pointer/where to buy:
the female canbus connector of the bms slave board, see picture.

I've seen it somewhere on the web, someone mentioning it to be a AMPS connector?

Thanks
best Carel Hassink

 

[Tomdb]

It is not a canbus connector.

it is a Molex 15-97-5101

https://www.digikey.com/product-detail/en/molex-connector-corporation/15-97-5101/WM4772-ND/1624637

https://www.mouser.co.uk/ProductDetail/Molex/15-97-5101/?qs=%2fha2pyFaduhUBYMHOhpw0rm86c0pAqJsWA1bXZwWo%2fM%3d

 

[CarelHassink]

Thank you for the prompt answer, and sharing

should make my customers happy,
if they want to make a bespoke can-bus loop.

I have put this info in a safe place now..
always willing to return a favor.

thanks,
Carel

 

[CKidder]

Thank you for the prompt answer, and sharing

should make my customers happy,
if they want to make a bespoke can-bus loop.

I have put this info in a safe place now..
always willing to return a favor.

thanks,
Carel

It is, once again, not a CAN bus loop. It's a TTL serial loop running at 612500 baud. If you try to put a CAN transceiver to those wires it just won't work.

 

[Kevin Sharpe]

Can I ask in this thread some pointer...

Seen this project with contributions from Collin and Tom?

https://hackaday.io/project/10098-model-s-bms-hacking

 

[CarelHassink]

Hello All,

"it may wel be not the correct forum to post this...but...."" with thanks,
it's obvious Im greatly interested in the progress making the Tesla bms work.
I had some clients that are using the software from Github.

Thanks for showing me the Hackaday project.

Except Jack Ricard's product, aimed at the US market
would anyone know of one aimed at Europe,
and perhaps able to work with SMA inverter/chargers,
since a new SMA product is coming into the solar energy market.
SMA Sunny Boy Storage 6.0 high voltage operating from 100V to 550V DC.
I will be launched in USA Europe and Australia coming February

see:http://files.sma.de/dl/31186/SBS37-60-DEN1751-V21web.pdf

Nice to have this Storage Boy 6.0 working on Tesla steroids..

best Carel

 

[Tomdb]

I have now gotten the Simple BMS (running Tesla BMS code) to talk to Victron system.

This will allow me to do cycle testing through using one of their Multiplus charger inverter modules.

Implemented features in the code:
-Balancing now happens to the lowest cell voltage instead of voltage setpoint
-SOC calculation has been cleaned up and tuned
-When starting the SOC is estimated at resting cell voltage
-CAN communication, to a format excepted by the VEcan system, will probally work with other solar inverters chargers out there

Upcoming features:
-SOC correction based on a full and empty battery
-Working on the Setup Menu so all necessary parameters can be changed on the fly.
-Looking to possible have add on modules for CAN based charger control (Lear Charger, Tesla Open Source and any that I can find online)

https://github.com/tomdebree/TeslaBMS

 

[Tomdb]

Update 16/02/18

Work on the BMS system specifically has stood a bit still, however been plugging away on the code. Ofcourse thank you to everyone who has contributed so far, Ckidder and Jarrod.

Github

https://github.com/tomdebree/TeslaBMS

New features:
-Canbus now running at 500 kbps (Verified to still work with Victron, Boekel request)
-CAB300 working (reason the canbus went to 500kbps)
-Switching between sensor types, CAN or Analogue

Does anyone have any other CANbus sensors for the more power hungry users? As 300 amps is quite small for some of us (Damien )

And ofcourse, open source it all. I take no responsibility if you wreck you things or others property due to your lack of knowledge or mistakes in the freely available code.

 

[Kevin Sharpe]

And ofcourse, open source it all.

Thank you

 

[Tomdb]

Ran a full - 4.1V average
to empty - As the inverter cut out at roughly 3.1V

This was a total drain of 92Ah, resulting in a remaining 8% SOC as i set the capcity to 100Ah. (12S tesla module)

I would say so far so good. Now just to get a more variable load to test the bms with.