QC Message Data Decoding

It appears that there are only a few "Messages" in a typical QC charging session.

As we decode more, we will post here.

There are some people who have the onformation we seek,
but they have signed Confidential Infornation agreements.
These people should NOT contribute here!!!!!

This is ONLY for information that is discovered in/from the "public world".

I've looked into this and to make it clear for any new people reading this thread, the QC canbus is separate from the EV/drivetrain canbus.
It is controlled by the onboard charger which has a data line that goes to the QC port exclusively
The only way this can be done is by hard-wiring a can-bus sniffer into the QC data line.
I'd do it, but there are yet to be any quick chargers available to the public anywhere in Canada.

I'm about to get access to a QC. I'm an electronics and software guy.

I can handle tapping into the signal line... what do I want to have for a sniffer?

Gary is selling a SOC meter kit based on the AVR-CAN that, among other things, will allow you to log can bus activity in the EV or car can via rs232 and his CanDo software. Just need to connect to the qc can bus instead.

FYI, I've heard LEAF owners participating in the VIP program, where owners get a little VIP in return for talking to potential LEAF owners, at the Nissan Test Drive events will get access to the Quick Charger. So it might be a chance that is relatively nearby to watch a Quick Charge for more data....

We have some QC-CAN data, and hope to post some for you all to see soon.

ElectricVehicle said:

FYI, I've heard LEAF owners participating in the VIP program, where owners get a little VIP in return for talking to potential LEAF owners, at the Nissan Test Drive events will get access to the Quick Charger. So it might be a chance that is relatively nearby to watch a Quick Charge for more data....

Click to expand...

We just had two days of that in San Diego, with one more day to go.

Messages on the QC CAN-bus:
(from observation of our QC-CAN traffic logs)

1. Messages 100, 101, and 102 seem to come from the LEAF.

2. Messages 108 and 109 seem to be replies from the QC machine.

By "simulating" a QC machine's first step after being connected
(apply +12v to a control pin), the LEAF sends 100, 101, and 102.

This "group" seems to be repeated about 10 times per second,
but it appears that the car gets "tired" of waiting for a response
in about 2 seconds, and it quits sending.

In operation, the car sends the current (in amps) that it wants
in an "Amps-Requested" byte in this group (values 0 to 120 observed).
More later.

Who wants to play?

The QC-CAN bus, like the three other CAN buses (EV, AV, CAR) in the LEAF, works at 500,000 (500 k) baud.

An AVR-CAN board (with its CAN interface) has been used to "watch" the QC-CAN bus, logging the CAN messages, just like we have been logging the 3 CAN busses that are available on the internal OBD connector.

Some analog and digital inputs have been used to capture the Voltage of the two Power lines and the 4 control lines.

CAUTION: Working around High Voltage can be dangerous.

After the Chademo plug is connected, the QC "asserts" +12v on one control line, and the LEAF responds with ... more later.

In the interest of understanding the QC process better,
and knowing how QC sessions affect the LEAF, I have
posted a 4-CAN Log of one 80% QC session, at:

http://www.wwwsite.com/puzzles/cando/" onclick="window.open(this.href);return false;

Caution: This is just one session, of one LEAF on one QC machine.
These logs should be helpful in investigating the QC process, but
do not contain enough data to implement QC safely and completely.
They are only an observation of a process for intellectual curiousity.

NOTE: Accidently, not all the CAN Messages were captured.

It's been a while since this thread was active, so I suspect the discussion has moved elsewhere, but I can't find it. I'm still confused about the CAN buses. I know there is are 3 CAN buses that are on the OBD port: the primary, the EV and the AV. This thread is about the fourth QC one, but where exactly can I hook into it? Do i use the standard OBD port and if so what are the pinouts? What is the format of the messages? I am pretty new to this, so I apologize if this is a very simple question that I should know. I am most interested in seeing the kW going into the car as a function of time. I gather that the rate is not constant and depends on SOC and temperature of the battery and ambient temp?

The kW into the car can be monitored from the OBD port with the Gidmeter. The CHAdeMO can is not accessible through the OBD. It is monitored through the CHAdeMO port.

The car controls the charging based on set parameters such as those you mentioned.

This thread has more info: http://www.mynissanleaf.com/viewtopic.php?f=26&t=7764" onclick="window.open(this.href);return false;

The QC CAN bus is not "easy" to access.
It is only in the LEAF's QC wiring and not connected
to the OBD connector or any other CAN bus.
It is between the QC Port (Socket) and the
Charging Controller that is located "in" the car's
"charger", which can be found behind the back seats.

The "easiest" access appears to be near the QC Port
in front, but great care should be used if trying this.

The GID-Meter reports the Voltage and Current
going Into/Out of the LEAF's Battery Pack.
In the case of L1 or L2 charging, that is NOT the same
as the current or voltage or power going into the car.

However, in the case of QC use, the car's Charger and
other electronics do use some power, but usually a very
small amount compared to the Power/Current going "directly"
into the LEAF's battery.

So, by Logging the EV-CAN bus, the QC power flow is essentially well
monitored by watching the Pattery Back Voltage and Current values.

Thanks for the answers. That makes sense. Monitoring the QC can directly sounds a little more involved than I thought, but it's nice to know the answer. However, it seems like you can infer qc from the charging rate monitored through the ev Can bus. As I understand, the charger may be putting out slightly more for operating the electronics in the car. Seems like that could be estimated.

A low tech way: The Eaton QC has a display that shows the voltage, amps, kWhs delivered and the time (counting down from estimated). You could take snapshots at timed intervals or video.

garygid said:

...
So, by Logging the EV-CAN bus, the QC is essentially well
monitored by the Pattery Back Voltage and Current values.

Click to expand...

On Tony's LEAF at Ashland this morning I terminated the QC manually, when around 80% on the LeafCAN SOC the amps were still in the -60A range, and the 9th Battery Temp Bar ( "BTB" ? ) had just popped up. I switched to L2 for another 33 minutes, ending at 263 gids.

263 / 281 => 93.59... => 93.5% GIDs (the 0.09 truncated).

It probably displays as 93.6% on that 2x16 LCD meter,
which probably "rounds" the 93.59 to 93.6%.

My F1.08 firmware truncates instead of rounding, to avoid giving
the (very small) impression of too much remaining energy.

Here is a product for monitoring and analysis of a chademo charger.
If you zoom in on the screenshots you can see sample messages and most importantly the timing tolerances for replies.
http://www.interface-amita.com/images/prdc/solution/explain.pdf

Nice find, the timing max and min shown for the 3 CAN Messages
from the car to the Chademo (101, 102, and 103) and the 2 response
messages from the Chademo to the car (108, and 109) are the first
"leak" of Chademo specs that I have seen.

However, there is the modest possibly that the values might be "faked"
just for this little inset example of their data timing analysis.

We will know soon enough - the spec is going to be public soon.