BMW i3 CCS/charge port controller

[Jack Bauer]

muehlpower has taken care of that.

Few pics from yesterday

[Jack Bauer]

Raw shaky phone video from yesterday. I won't post this to pootube as I'll just get ten comments complaining about the audio and another twenty wanting me to fix some obscure problem with their Tesla. Hope to have a bit more in a few days.

[mikeselectricstuff]

Don't you just hate those chargers that don't even show charge rate.
Saw a video recently (Gridserve's Ecotricity replacements I think), which actually showed voltage, current and kW - that's what we want!

[Jack Bauer]

Now all we need is to know how to ask the LIM for V2H mode:) Perhaps our CCS expert can tell us? Once the dust settles a bit I'm doing some reverse engineering on the 2014 lim to find the spi comms between the mcu and the qca7000 and hit it with a logic analyser during a ccs session.

[EV_Builder]

Question: Do both LIMS (2014/2017) work with the same code in the VCU?

[davefiddes]

If you get an SPI capture I'd be happy to knock up a script to convert it to a pcap file that can be opened in Wireshark to have a squint. I thought that CCS comms were secured with TLS so it might not mean much though.

Back to LIM integration. What are the plans/thoughts for completing the integration? If I'm understanding things correctly the VCU is the part of the system responsible for deciding what the current demand should be. So the VCU needs to decide how much charge based on the battery SoC and temp the then command the CCS station via the LIM. We need some code that does all of that during a charging session and provides on-going charge time estimates?

[Jack Bauer]

Thanks for the work on the LIM software Dave:) Much appreciated.

Today went for a bit more power. 25kw. Had to use the less powerful power company charge point today as my stupid bank insist on this text verification nonsense when ionity do a pre authorisation of 1 euro for every session start. This drives the app loopy and the charge point won't authorise.

Did a few tests :
1)Shutdown session, drive car, new session. No problems
2)Shutdown session, start new session. no problems.
3)LIM weld detects when cp door closed and ign on but happy to restart a session if not done.
4)My stupid cc/cv software actually sort of works.

[EV_Builder]

Don't you just hate those chargers that don't even show charge rate.
Saw a video recently (Gridserve's Ecotricity replacements I think), which actually showed voltage, current and kW - that's what we want!

From an UX perspective you would say not interesting for normal users. But if you then look to that UX they made you would expect the complete surface used and the time remaining in font size 100 etc.

A button details (with the data you say) would then kill it i think.

[muehlpower]

On i3-High-voltage-ComponentsGB.pdf you can read on page 127 that the welding test after completing the DC charge is normal

"For DC charging the LIM closes the two switch contactors in the KLE, thus enabling the shift through
from the direct current voltage from the DC charging station to the high-voltage battery. The LIM tests
after every completed DC charging procedure the DC switch contactors so that a switch contactor
label (switch contactor cannot open the contacts) is identified. A switch contactor label (single or
double) is identified by the LIM and sent to the EME as a fault code. If during the charging procedure
no valid pilot signal is identified by the LIM, the LIM must open the DC switch contactors within
200 ms."

[EV_Builder]

What we need is the magic board for the voltage signal and preferably also equipped with the relais conversion magic.
Maybe we should add some amplifiers for external LED rings etc .
Some thoughts.

[Jack Bauer]

Yeah not a bad idea. I suspect there will be quite a few addons made for the LIM.

@davefiddes re the LIM / VCU integration my thoughts would be the basics like cc/cv with user setable limits etc. There is a world of extra functions that can be added if required after that.

I'll need to figure out a good bit more like the "hotel function" for timed charging, led modes etc. From what I've seen over the past few days the LIM is the ideal charge interface. VERY fault tolerant and won't let you do stupid stuff like say....wire the contactors wrongly!

I'll test the 2014 LIM in a few days but I'd like to say it should just work.

[muehlpower]

What we need is the magic board for the voltage signal and preferably also equipped with the relais conversion magic.
Maybe we should add some amplifiers for external LED rings etc .
Some thoughts.

I divided it into three boards. The voltage sensing board is in the box with the DC contactors so that I don't have to pull the HV through the car. On the second there are relays and resistors to make the LIM satisfied and to be able to control larger contactors with economizers. There is also another small relay with resistors that simulates the Phoenix interlocking because I use a cheaper DUOSIDA socket. The thyristors for the LEDs are housed on the board together with the LEDs, as next to the charge port.

[bji900]

Just picked up a 2014 and 2017 i3 LEM with DCFC from US cars that were crashed, looking to help where I can. For the guys with the LEMS working, did they come from wrecked cars where the airbags went off? Just want to document the state of the LEMs in case we find that an airbag or safety event disables something in the LEM. I doubt it, but work documenting.

[Jack Bauer]

My 2017 LIM is from a crashed car and the bags most certainly went off in that car. For folks looking to help can we please get as much info as possible into the wiki page. I know its not sexy but is super important.
https://openinverter.org/wiki/BMW_I3_Fa ... LIM_Module

[Bryson]

Just bought a brand new one, figured I might as well contribute by making sure that a VIN-less LIM still plays nice.

[Jack Bauer]

Cost? This also needs to go in the wiki :
New LIMs will need to be coded using a BMW service tool like ISTA+ before they will work. I have the software to do this and have ordered some cables so I'll hopefully be able to advise on this soon.

[Bryson]

$270USD - looks like I’ve got to get back into the world of BMW hacking again! Cool, thanks for the heads up.

edit: purchased here https://www.ecstuning.com/b-genuine-bmw ... 356828052/

[Jack Bauer]

Very good price:)

[bji900]

The limits for pre 2017/26 are 0V-500V 0A-250A, post 2017/27 0V-1000V -500A-+500A.

Where is this information coming from? Just want to verify for the Wiki, Also what does 2017/26 mean is that year/week, from the date on the module sticker??

[Jack Bauer]

week 26 2017. Info is accurate.

[EV_Builder]

What we need is the magic board for the voltage signal and preferably also equipped with the relais conversion magic.
Maybe we should add some amplifiers for external LED rings etc .
Some thoughts.

I divided it into three boards. The voltage sensing board is in the box with the DC contactors so that I don't have to pull the HV through the car. On the second there are relays and resistors to make the LIM satisfied and to be able to control larger contactors with economizers. There is also another small relay with resistors that simulates the Phoenix interlocking because I use a cheaper DUOSIDA socket. The thyristors for the LEDs are housed on the board together with the LEDs, as next to the charge port.

Ok i figured since we wanted to control the larger contactors also i thought it could be one board in the box with the DC charge contactors indeed.
I sure want to use the LIM as intended. The locking part of the socket is indeed a good point. We will need something thats flexible enough for multiple types.

I bought an ID3 CCS2 socket with cabling.

Count me in for those boards.

I'm still in the construction phase of the car so sorry if i can't contribute more to the software.
What i do wanted to make is a class so we can make a table.
The table allows you then to ask for a pre-programmed value from it (linear interpolation).

So for example we define voltage on one axis and charge current on the other.
Then we can automatically tune the DC charge process by once per second asking the table for the charge current.
(the input we give to the class is then the Pack Voltage).

Next phase would be making it 3D then we can interpolate also against Pack Temperature (for example).

For the motor tuneing i had something similiar in mind but i don't know yet which vars are there / tweaks.

Let me know Damien if this would help with your CC/CV requirement etc.

[CCSknowitall]

First off, congrats to Damien for getting this working! You tested on an ABB which is great, they are particularly picky about isolation.

I’m working on finding an inexpensive PLC monitoring solution so we can verify the can vs the plc side. I’m also trying to get a plc log of a stock i3, to see its plc “accent” if you will :p. Unfortunately I am really busy for a short while, and it will probably be a bit before I capture an i3 plc log. As soon as I can, I will.

As far as the “negative” current ability, I think this is a vestige from the CHAdeMO code. In Japan, cars by law must support v2g, and I believe this defacto means CHAdeMO v2g support is mandatory. DIN 70121 (pre ISO 15118) does not support bidirectional, nether does ISO 15118 except for the latest -20 version. I can’t wait to see what the car is saying for this negative value.

[CCSknowitall]

I should add: for anyone considering adding this to their conversion, please heed this warning:

You must absolutely have a functional locking connector. It is imperative for your safety, your vehicle’s safety, and the safety of the general public. Electricity does not give second chances, high voltage DC especially so.

[EV_Builder]

I suggest we should add to the board some type of lock release.
Should be one input from VCU AND'd with the coil signals not being present etc. On reset of everything VCU can send a reset pulse to unlock?
If we then reset the car the charger for sure will stop charging and the lock will open up
Then we have an escape and it's save. (coils are not closed) etc.

[Jack Bauer]

Most of the locks now have a pull cord manual release. I agree re safety aspects and will be fitting one myself. My reasons for not using one during this testing phase are sort of personal to me and a bit long winded. This is again where the LIM is the ideal charge port controller as it has all this included for us.