Let the hacking begin... (Model S parts on the bench)

[wk057]

Would this latter idea also open up potential to use CAN bus message(s) for charging status...?

Charging status is on the power train CAN bus.

 

[HankLloydRight]

Would this latter idea also open up potential to use CAN bus message(s) for charging status...?

So we'd need to tap/log/filter two different CAN busses to get charging status, unless we can find something else on the body CAN bus like lighting up the charge port.

 

[wk057]

So we'd need to tap/log/filter two different CAN busses to get charging status, unless we can find something else on the body CAN bus like lighting up the charge port.

The charge port sits on the power train bus for sure. I don't think there are mirrors of that on the body bus.

 

[faughtz]

So thanks to all of you, I have cell voltages:

But look at 65-72.
Thoughts?

 

[MikeBur]

The charge port sits on the power train bus for sure. I don't think there are mirrors of that on the body bus.

wonder if the charge door status is on body bus then? ;-)

Not perfect, as not indicative of active charging status, though would be better than nothing...

 

[Ivo-G]

Ok, I understand. What I can contribute is testing data from Europe. I'm only 1 hour away from the autobahn where I can do some testing at full throttle.
I love playing around with this stuff and learning about all possible details of the car so I'd like to buy a CAN bus logger that allows me to get a maximum of data to do so.
I'm sure I would be able to help some folks in Belgium and the Netherlands that have questions on their battery health and things like that.

From what I understand, right now the SavvyCAN is probably the easiest option but I need to find a way to get it shipped at a reasonable cost. The list price of $295 is fine but adding $190.79 for shipping + probably an additional European import tax + VAT on top looks a bit much in comparison with the list price.

Respect for the work you and others are doing to offer all of this to the community for rep points only!

For what it's worth (coming from a junior member you also don't know personally or on this board), Jan (jpet) is a very admired and valued member of the Belgian and Dutch Tesla community, and one who's views and methods are always much respected and valued by those lucky and smart enough to listen to what he has to say.

I'm not quite as far as he is as I don't have my car yet, but I certainly intend to learn as much as I can about the inner workings of the Model S. And so far he's the one I've learned from the most.

 

[LetsGoFast]

wonder if the charge door status is on body bus then? ;-)

Not perfect, as not indicative of active charging status, though would be better than nothing...

I spent some time looking for it this morning and I don't think so. Appears to only exist on CAN-3, it appears that the light and the door open/close are all on the same message.

 

[glhs272]

So thanks to all of you, I have cell voltages:


But look at 65-72.
Thoughts?

Wow, looks like Module 12 is way out of balance with the rest of the pack.

 

[apacheguy]

So thanks to all of you, I have cell voltages:

But look at 65-72.
Thoughts?

Yikes. Doesn't look good at all. Are you sure there isn't a bug in the reporting algo? Seems too far off to believe that the BMS wouldn't pick up on that.

 

[Zextraterrestrial]

Wow, looks like Module 12 is way out of balance with the rest of the pack.

11 & 12
Oh. Way more for12 though but 11 vs the rest is a bit high too
Is there 6 cells per module? If so 2 of 11 are high? Or am I looking at it wrong

 

[wk057]

So thanks to all of you, I have cell voltages:


But look at 65-72.
Thoughts?

I assume you're using the updated code for calculating the voltage? I made a correction to Jack's initial method here: Let the hacking begin... (Model S parts on the bench) - Page 64

Although, I don't think that would account for such a discrepancy. You might have some groups of cells with a couple of bad fuses if those numbers are right. Since you're seeing two sets of four voltages in a row reading incorrectly (ie, two CAN messages) I think it's more likely a reading/parsing error.

 

[jpet]

But look at 65-72.
Thoughts?

What happens when you do another capture when the car is at a lower SoC?
Do all cells go down in voltage and are cell 65 to 72 still at a significantly higher V than the rest?

 

[faughtz]

What happens when you do another capture when the car is at a lower SoC?
Do all cells go down in voltage and are cell 65 to 72 still at a significantly higher V than the rest?

I don't think it was a parsing or algorithm issue. It occurred over multiple captures. It was surprising to me that there was this much imbalance. However after about 10 miles this morning, I captured this:

I am using the updated conversion factors. Thanks wk057; and what a valuable asset your bench will be.
As I have never charged beyond about 60kWh (P85D), I thought this might be more info, but maybe not.
Looking forward to more discovery.

 

[jpet]

I don't think it was a parsing or algorithm issue. It occurred over multiple captures.

When I saw it at first, I was also thinking about variables that were not initialized properly and still had a previous value in them. Don't know it that is even possible with the software you are using to present the values.

It was surprising to me that there was this much imbalance. However after about 10 miles this morning, I captured this:

I am using the updated conversion factors. Thanks wk057; and what a valuable asset your bench will be.
As I have never charged beyond about 60kWh (P85D), I thought this might be more info, but maybe not.
Looking forward to more discovery.

Good to see that the issue got resolved. I also charge my car to a SoC of 70% if I don't need the range. But, I do a range charge at least once every 2 months to trigger the balancing. Can't wait to receive the CAN bus logger I ordered to see what my daily cycling between 30 and 70% SoC really does to the cells. I will finally be able to find out how fast they tend to go out of balance.

 

[andrewket]

When I saw it at first, I was also thinking about variables that were not initialized properly and still had a previous value in them. Don't know it that is even possible with the software you are using to present the values.



Good to see that the issue got resolved. I also charge my car to a SoC of 70% if I don't need the range. But, I do a range charge at least once every 2 months to trigger the balancing. Can't wait to receive the CAN bus logger I ordered to see what my daily cycling between 30 and 70% SoC really does to the cells. I will finally be able to find out how fast they tend to go out of balance.

What is your rated range at 100%? Mileage?

 

[faughtz]

What is your rated range at 100%? Mileage?

I have never paid much attention to rated range, I use % charge, and typically drive about 100 miles/wk.
Probably not clear above, but even when I was at a few % charge and charged to 100%, I never saw more than 60kWh going in. Doesn't make sense, esp with losses. Very interested in better understanding true capacity.

 

[Cyberax]

BTW, what's the pinout on the FAKRA Ethernet connector? I'm getting my cables tomorrow (finally).

 

[obrien28]

BTW, what's the pinout on the FAKRA Ethernet connector? I'm getting my cables tomorrow (finally).

Ask and you shall receive. This pinout seems to be consistent across model years, however the connector location may vary, the early cars had it behind the drivers side end cap, while newer ones (VIN >60K) bundle it together with the TDC under the dash.

Shell connector reference:

Pinout
TX+ = 1
TX- = 2
RX+ = 3
RX- =4

 

[MikeBur]

I spent some time looking for it this morning and I don't think so. Appears to only exist on CAN-3, it appears that the light and the door open/close are all on the same message.

Ho hum, thanks anyway. I don't believe there's even a CAN power bus access port in the rear is there?

rep in your inbox for trying though

 

[jpet]

What is your rated range at 100%? Mileage?

All of my range charges can be found in the MaxRange Tesla Battery Survey sheet. Search for jpet
I have ordered a CAN bus logger because I want to get beyond the calculated Tesla rated range figure and I also want to get a better understanding of why / when my car gets power limited when I push it.