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

[wk057]

Me too. The real world range and performance reports also support this fact: the the difference between the "85" vs "60" battery is quite a bit less than 85/60=1.42 would suggest. More like 77/59.8=1.29. Worth the $$$? It's a subjective choice but one easier to make correctly if we were given fair and correct info (just like the 691 hp and what-not).

Even if you just go by RWD version mileages this should have been evident: 265/200 = 1.33 ... pretty close to 77/59.8 = 1.29. Definitely more realistic than 85/60=1.42. The weight difference between the 60 and 85 kWh packs is something like 200 lbs, definitely not significant enough to account for such a discrepancy in range either.

*shrugs*

<rant>
I don't want to derail my own thread here, but in all honesty (and I just posted this in another thread) I now have zero trust for Tesla. I no longer believe any published spec or advertisement/announcement is truthful. If there was any trust left at all, figuring out the real "85" kWh capacity wiped out whatever was left. When they released the P85D, Tesla used (read: abused) the trust I did have previously to basically swindle me into a pricey trade-up for very little real gain and a promoted feature set that was essentially paid for but unusable until a year later. The way I see it I paid for 691 HP, 285 miles of range, autopilot before summer '15, and an 85 kWh battery. The reality is that I received 463 HP, 247 miles of range, autopilot a year after purchase, and a 77 kWh battery. Sorry Tesla, not falling for your crap ever again. As my own protest I sold off 100% of my rather long TSLA position several months ago (nearly ~3k shares all together). I no longer even own a single share of TSLA because I have no longer have any faith in the company to be honest with customers. That's a surefire way to drive a company into the ground, and I'd have to be an idiot to keep a large investment in such a company.

Now, here's the funny thing. As a 463 HP, 247 miles of range, 77 kWh, AWD EV with autopilot.... it's an amazing damn car. There was absolutely zero need to promote fake specs and lie about the car when the real specs are already the best the market has to offer. It just makes no sense to me whatsoever that Tesla has decided to just promote false and misleading key specifications in order to get more sales in the short term while people slowly work out the truth.
</rant>

Back to hacking...

 

[smac]

Keep in mind that the battery total charge and discharge includes regen. So while the dash Wh/mi numbers will show the net result after regen, the battery total numbers do not. For example, if you start at a stop, accelerate until you utilize 1 kWh, then regen to a stop, both the charge and discharge lifetime values will increase accordingly, while your dash will show the net of discharge minus regen. The lifetime counters only count up, never down.

Yep I sort of assumed it was the total that had gone through the pack. Effectively regen has "saved" me £220

Additionally, the BMS appears to keep track of its mileage on its own based on messages from the rear drive unit for speed. Mine is actually pretty accurate compared to the dash (+/- 1%), so unsure why yours is so far off. Wonder if your battery was in fact partly used. That'd be interesting.

That is certainly a conundrum. I'd partially assumed it was the BMS basing it from driven miles vs. rated. The 60 packs may be used / binned or well who knows. I certainly don't think I have anywhere near enough evidence to write a letter to them.

Seeing a 60 pack report a full capacity at 59.8 kWh and the 85 kWh packs reporting ~77 kWh does kind of make me a bit angry, admittedly, and fits my original predictions/assumptions from earlier almost exactly.

The whole 60/85 thing never made sense to me. The numbers have never added up.

The "hump" in the pack seemed like a last minute engineering change to crack 300 ideal miles for headlines, and using dummy cells seemed a logistical PITA. FWIW I've long suspected the 70 was the "original intent" for the car.

Look on the plus side though, I have got much worse performance, and it's blatantly clear Tesla have no love for the 60 owners in the EU. I get a distinct impression they wish they'd never had the car on the design studio here.

I'd love to see a log from a 70!!

 

[green1]

As my own protest I sold off 100% of my rather long TSLA position several months ago (nearly ~3k shares all together). I no longer even own a single share of TSLA because I have no longer have any faith in the company to be honest with customers. That's a surefire way to drive a company into the ground, and I'd have to be an idiot to keep a large investment in such a company.

If you get angry at them again, can you protest by telling me how to root my car? (being that you're out of shares to sell off...)

 

[pgiralt]

The real question now is how much capacity does a 90 pack really have?

 

[kennybobby]

Nothing feels better than a good rant to help get it out of your system...Well almost nothing,

Look a Kitten...

 

[wk057]

If you get angry at them again, can you protest by telling me how to root my car? (being that you're out of shares to sell off...)

lol

The real question now is how much capacity does a 90 pack really have?

My guess, based on rated miles, is probably about 81-82 kWh usable, or 4-5 kWh more than the "85". Would be cool to get some CAN logs. If anyone with a 90 or 70 is anywhere nearby and would let me plug up to their diagnostic port to snag some data, that'd be very nice of you.

 

[glhs272]

Even if you just go by RWD version mileages this should have been evident: 265/200 = 1.33 ... pretty close to 77/59.8 = 1.29. Definitely more realistic than 85/60=1.42. The weight difference between the 60 and 85 kWh packs is something like 200 lbs, definitely not significant enough to account for such a discrepancy in range either.

I am not saying I know anything more about this than you do, but, even when my 60 was new I could never get close to actual 60kwh out of the battery. 55kwh is about it. That would get me about 208 rated miles (not 200). Therefore the correct rated miles ratio should be 265/208=1.27. I have been keeping track of the degradation (hasn't been much), so we will see how that changes. I have seen 77kwh (edit 77.5) out of an 85kwh battery (Bjorn), so I think the 77/55 = 1.4 (edit 1.41) ratio is more closely aligned with usable reality than 77/59.8 is, despite whatever you are seeing in your hacks.

 

[smac]

<rant>
...
Now, here's the funny thing. As a 463 HP, 247 miles of range, 77 kWh, AWD EV with autopilot.... it's an amazing damn car. There was absolutely zero need to promote fake specs and lie about the car when the real specs are already the best the market has to offer. It just makes no sense to me whatsoever that Tesla has decided to just promote false and misleading key specifications in order to get more sales in the short term while people slowly work out the truth.
</rant>

Thing is even at 320bhp with 200 miles and no AP, it's an amazing car. Despite having a faster weekend toy, I still love the Tesla and don't know what else I will swap it for.

Ironically I only bothered getting into this because I have felt lied to from day one when dealing with Tesla. I have never had this urge to go reverse engineering any other car I've owned.

<speculative rant>
The only half logical reason I can come up with is we are missing people who can kick Elon in the shins when he opens his mouth still at the point the engineers haven't even worked out if this promise is vaguely deliverable.

</speculative rant>


Anyway back on track. I'll continue wherever I can with the hacking and the 60 peel back...

- - - Updated - - -

I am not saying I know anything more about this than you do, but, even when my 60 was new I could never get close to actual 60kwh out of the battery. 55kwh is about it. That would get me about 208 rated miles (not 200). Therefore the correct rated miles ratio should be 265/208=1.27. I have been keeping track of the degradation (hasn't been much), so we will see how that changes. I have seen 77kwh out of an 85kwh battery (Bjorn), so I think the 77/55 = 1.4 ratio is more closely aligned with usable reality than 77/59.8 is, despite whatever you are seeing in your hacks.

I have drawn 56kWh out of mine at 12k miles old (c. 190 miles)

Do you have an A or a B pack ?

 

[glhs272]

I have drawn 56kWh out of mine at 12k miles old (c. 190 miles)

Do you have an A or a B pack ?

I guess I have never run mine to full stop. The most I have tried to get out of it was 54.9kwh, that was with 5 more rated miles left. So I guess that points to about 56.5 kwh usable capacity. B pack.

Edit: And I thought I was doing good with this run... I guess I should have been shooting for 59kwh?

 

[AWDtsla]

Even if you just go by RWD version mileages this should have been evident: 265/200 = 1.33 ... pretty close to 77/59.8 = 1.29. Definitely more realistic than 85/60=1.42. The weight difference between the 60 and 85 kWh packs is something like 200 lbs, definitely not significant enough to account for such a discrepancy in range either.

*shrugs*

I'm still scratching my head over this one. The only thought I have right now is what if the thermal losses inside the battery are so large in comparison the drive usage, that adding more batteries significantly increases the total energy used. Ok that could apply to all the lines and inverter too.. Maybe an experiment like having both cars in valet mode then do energy usage comparisons.

The weird thing is the math in the cars for rated miles reconciles. But then again, I see the trip meter is totally wrong and my actual power usage around 70% more than reported by any of the 3 trip counters. So it was probably just programmed that way.

<rant>
I don't want to derail my own thread here, but in all honesty (and I just posted this in another thread) I now have zero trust for Tesla. I no longer believe any published spec or advertisement/announcement is truthful. If there was any trust left at all, figuring out the real "85" kWh capacity wiped out whatever was left. Then they released the P85D, Tesla used (read: abused) the trust I did have previously to basically swindle me into a pricey trade-up for very little real gain and a promoted feature set that was essentially paid for but unusable until a year later.

I've never driven a P85D, but driving a P85 after P90D, I wouldn't put the difference "little real gain". It feels like going from amazing to completely mundane. Extra capability used almost constantly.

 

[smac]

I guess I have never run mine to full stop. The most I have tried to get out of it was 54.9kwh, that was with 5 more rated miles left. So I guess that points to about 56.5 kwh usable capacity. B pack.

Edit: And I thought I was doing good with this run... I guess I should have been shooting for 59kwh?

Here's mine (B pack also)

FWIW with an EU car I set off with 172 miles on the display. It is impossible to make my car show over 200 miles irrespective of settings

I should add 50% of that was with cruise control set to 70mph.

 

[supratachophobia]

The real question now is how much capacity does a 90 pack really have?

This is truly the real question. Is this an attempt to "make it right" like the p90d ludicrous mode was?

 

[AWDtsla]

This is truly the real question. Is this an attempt to "make it right" like the p90d ludicrous mode was?

According to the rated mile math it's not. Let's say P*D is rated at 310 Wh/mi, as reported by the energy analyzer. Then 253*.310 = 78.4 kWh, and 267*.310 = 82.8kWh, or approximately the advertised capacity minus ~6-7kWh for each battery. But my assumption was this is bricking reserve plus charging reserve, maybe it can be proved otherwise.

edit - but I agree it's pretty disappointing to advertise a capacity that is never usable. Almost as disappointing as the car lying to me everyday about the energy it has used.

 

[supratachophobia]

According to the rated mile math it's not. Let's say P*D is rated at 310 Wh/mi, as reported by the energy analyzer. Then 253*.310 = 78.4 kWh, and 267*.310 = 82.8kWh, or approximately the advertised capacity minus ~6-7kWh for each battery. But my assumption was this is bricking reserve plus charging reserve, maybe it can be proved otherwise.

edit - but I agree it's pretty disappointing to advertise a capacity that is never usable. Almost as disappointing as the car lying to me everyday about the energy it has used.

Anything we can do about it? I guess the argument is the car goes as far as it is advertised (probably a big reason they didn't do EPA certification for 90kw). But the argument to that is, no one ever sees rated range under anything but ideal conditions (like 10% of the time maybe). You add a little HVAC and highway speeds, then forget about it.

 

[DrJeff]

Remember when hard drives were advertised with X Mb storage, but due to formatting they could never actual store that capacity. There are precedents for advertising vs real use being disconnected.

 

[Danal]

Does anyone with CAN monitoring equipment know, or can you do a quick experiment and find out:

On the CAN2 (body) bus, does message 504, which shows headlight and tail light status, does that message repeat in "near real time" as turn signals flash?

 

[wk057]

Welcome to the battlefield.

Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

 

[obrien28]

Does anyone with CAN monitoring equipment know, or can you do a quick experiment and find out:

On the CAN2 (body) bus, does message 504, which shows headlight and tail light status, does that message repeat in "near real time" as turn signals flash?

Based on my in car time it appears they do, there is also a special ID that displays whether or not you enabled the emergency flashers.

I have PM'd you with a special link to my GDocs spreadsheet that has some more detailed information.

 

[chickensevil]

Wk, I have a brand new 90D that I would be happy to throw into the mix and am relatively speaking to most in this thread, "just down the street" from you. I am in Northern VA so would be happy to drive down some weekend. Plus it would be cool to check out your setup! Happy to help in whatever way I can

I figured I was so late to this party noone would need my help,

 

[garygid]

Cautions on attaching to an existing CAN bus:

1. Keep the attached lines fairly short, and do not terminate the +/- pair with a Resistor.
The two required termination resistors will already be at each end of the existing bus.

2. Avoid Writing to the existing bus, since that can change the timing of other messages.
Eventually, we might learn enough to be able to write something meaningful to the car,
but even then the writing is likely to interfere with other messages. So, for now, no Writing
when dealing with a real moving 2.5 ton vehicle.

3. In real CAN message Receiving, the receiver supplies (writes) an ACK bit to the bus.
If your Reader writes this ACK bit, you will likely interfere with the intended recipiant.
So, to just Listen in, you must configure your hardware to Read but NOT write the ACK bit.

4. Real CAN hardware includes several buffers (usually a dozen or more) to be used to receive messages,
to allow receiving two or more messages that are head to tail (little or no space/time between them).
Some simple CAN support libraries do not include support for these extra registers, and these libraries can
appear to work well, but they will miss a message that begins too soon after the end of the previous message.

There are some applications where one is logging just infrequent messages, or often repeated messages,
and one does not care if occasional messages are dropped (not received). But our goal was to log all the
messages, for doing a more complete analysis while investigating the meanings of the messages.

-------------
All these warnings from experience.

So, we do not terminate existing buses, do not Write or generate ACK bits,
and only Listen (passively) by using multiple CAN hardware receive buffers.