DC Throttling "battery conditioning"

[RWerksman]

Yeah, that's yet another way Tesla did 85kWh battery owners dirty. The charge throttling—even on rarely fast-charged batteries—is almost a crime. All so they can save some money and not replace battery packs under warranty.

We're coming up on the end of year 7 of our warranty, and I'm getting pretty nervous having this car for another year (or longer).

I have about 6k miles left on the CPO warranty of the 90D that I purchased last year. The wife and I were debating moving from the R1T reservation to an R1S reservation that she could use instead, with me keeping it longer.

Long story short - no, no I don't think I will.

An out of warranty Model S is a bad place to be. That single point of service (pretty much) is a virtual death sentence to your wallet if you need something repaired. Russian roulette of the wallet. Ironically, I think my insurance company knows that in general with the Model S as the R1T insurance charge is less than half of Tesla.

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[Nolf]

It should get better pretty quickly.

No doubt. With the blue chip auto makers throwing in (although Toyota seems to be slow - maybe working on something just not ready to share) it will be a rapid rise. Battery tech should benefit as well. Charging infrastructure, etc.

 

[moosehead]

Agree. If I were one of the few and proud that needed the max pack, I would be waiting for 800v. Who knows, seems unlikely, but perhaps pre-march-1 max pack preorder holders will get 800v, new in-house motors, etc.

This may not be far off given product shortages and delays, or perhaps as an upgrade option for those few.

 

[pc500]

If ya'll haven't noticed, the wonky ass charging curve has been bothering me since @timesinks posted his first curve. Thankfully Kyle Connor livestreamed his trip back to Colorado from Phoenix. I went through and logged the curves from the latter half of the day, and it was very clear that battery conditioning was the cause of a couple of throttling events. Kyle was pretty convinced that it was because the battery wasn't warm enough, and was eventually coldgating. YMMV, but keep an eye out for the "battery conditioning" warning that is on the screenshot below. It shows up when it starts conditioning the battery mid-charge. It doesn't warn you ahead of time or anything, and it doesn't actually do much based on how little it recovered while charging. Until Rivian implements either manual or automated battery preconditioning, it looks like we may need to be doing some yo-yo driving to try and heat the battery up.

So, here are the curves. The dashed one are the ones that had conditioning occur during the session, and it happend right when the charging speed dropped off. For context, Kyle had been driving at highway speeds all day. The coldgate events were when the outdoor temperatures were in the 30s to low 40s as I understand it. One session that didn't coldgate he yo-yo'd beforehand (and actually got limited regen). The other instances were closer to phoenix and earlier in the day, so I assume warmer.

He unplugged the yellow curve too early to see it come back off peak, but the blue and orange curves seem to be a fairly reasonable ramp down in speed to 80%.

All of the curves were limited by the 350Amp issue with EA, so the max speed seen was about 155kw. He tried to charge at a station that apparently should have put out 500 amps per Ryan Huber, but that was one of the coldgate curves.

Hope this helps, and hopefully Rivian issues some more proactive battery temperature management to reduce the number of poor charging sessions like these. Even if it's just manual.

How do you identify 500 amp stations with EA? Most of them won't do it.

 

[pc500]

People get all twisted in knots about the heat pump operation in very cold temperatures. Ours has worked great down to single digits, but that's not the point. A heat pump allows you to very efficiently extract heat from both the environment and from your motors. This heat is then available not only for the cabin, but also to to condition the pack while operating in temperatures outside of optimal, which in the Northeast, is most of the time. Our Model Y runs roughly 380 wh/mi at 70 mph in 30-40 degree temps. If you're approaching a supercharger, it will run the motors inefficiently to generate a bit of waste heat, which the heat pump uses to warm the pack. We typically see efficiency of around 550 wh/mi during this preconditioning phase, which it will use for 10-20 minutes at a time.

@Gator42 Regarding Model Y road tripping, we get around 3 hours between stops in the summer and 2 hours in the winter, assuming starting with 90% SOC and pulling in with around 15%. Most charging sessions we've experienced have been around 30-35 minutes to get to 80% to continue the journey. It's possible to charge for less time by stopping more frequently, but I don't prefer this given that most SC locations are not on main thoroughfares. While I enjoy the slower pace of EV road tripping, I do find the last 10 minutes of charging starts to feel a bit annoying. A 20 minute charging stop would be pretty much perfect. A 60 minute charging session to hit 80% would feel like an eternity, particularly without onboard streaming capability.

This is why I'm getting the maxpack. I can tolerate one charging stop of 30 minutes (lunch). 60 would be annoying. 400+400 miles = 800 which is more than I'd drive in one day. Usually, you can start the next morning at a full charge.

 

[pc500]

No, I get resistive heat and using waste heat, but in colder climates a HP sure would be welcomed efficiency both for cabin and battery conditioning. It has become both a standard and upgrade option on certain other EV’s, and certainly seems to help automatically precondition both heating and cooling in the Pcar and Audi lines.

Taycan Frank may chime in but presume that both the 800v architecture and the HP help the Taycan’s great charging curve and range efficiency.

Interested to hear Tesla owner’s experience as well, as they have had both recent HP additions and recall issues.

A HP makes a specific different in a certain temperature profile, but is generally more helpful on highly efficient vehicles. Like AC, it takes a certain amount of energy/hour to condition the cabin. My honda civic 4-bangar loses 1-2 mpg from running the AC. My truck 0.2 MPG at most. It is even more beneficial on highly efficient city-driven vehicles -- especially those with short range that don't have surplus range for city driving.

When you're needing range -- highway driving -- you're drinking energy like no tomorrow on a Rivian (it's highly inefficient as a truck), yet you take the same energy to heat as a Tesla. Tesla on the other hand wins the range game with efficiency.

It's hard to explain, but while it's nice to have it's simply less important. I want it because I like to sleep in the truck at rest stops while going across country, but that's a different matter.

 

[pc500]

If ya'll haven't noticed, the wonky ass charging curve has been bothering me since @timesinks posted his first curve. Thankfully Kyle Connor livestreamed his trip back to Colorado from Phoenix. I went through and logged the curves from the latter half of the day, and it was very clear that battery conditioning was the cause of a couple of throttling events. Kyle was pretty convinced that it was because the battery wasn't warm enough, and was eventually coldgating. YMMV, but keep an eye out for the "battery conditioning" warning that is on the screenshot below. It shows up when it starts conditioning the battery mid-charge. It doesn't warn you ahead of time or anything, and it doesn't actually do much based on how little it recovered while charging. Until Rivian implements either manual or automated battery preconditioning, it looks like we may need to be doing some yo-yo driving to try and heat the battery up.

So, here are the curves. The dashed one are the ones that had conditioning occur during the session, and it happend right when the charging speed dropped off. For context, Kyle had been driving at highway speeds all day. The coldgate events were when the outdoor temperatures were in the 30s to low 40s as I understand it. One session that didn't coldgate he yo-yo'd beforehand (and actually got limited regen). The other instances were closer to phoenix and earlier in the day, so I assume warmer.

He unplugged the yellow curve too early to see it come back off peak, but the blue and orange curves seem to be a fairly reasonable ramp down in speed to 80%.

All of the curves were limited by the 350Amp issue with EA, so the max speed seen was about 155kw. He tried to charge at a station that apparently should have put out 500 amps per Ryan Huber, but that was one of the coldgate curves.

Hope this helps, and hopefully Rivian issues some more proactive battery temperature management to reduce the number of poor charging sessions like these. Even if it's just manual.

I am also actually surprised the charging itself doesn't warm the battery enough. On the leaf, charging alone would overheat it, even in hot weather.

 

[SeaGeo]

How do you identify 500 amp stations with EA? Most of them won't do it.

There's not an easy way to do that right now. It seems like it's limited to ABB chargers, so it may also be primarily regional. From what I've seen so far, the folks in the PNW don't have as much of an issue.

I am also actually surprised the charging itself doesn't warm the battery enough. On the leaf, charging alone would overheat it, even in hot weather.

Same, but if you think about it it makes sense. The charging curve is pretty conservative relative to the pack size, relative to the overall capacity it's not pushing that much current. That's at least how I'm looking at it.

 

[pc500]

There's not an easy way to do that right now. It seems like it's limited to ABB chargers, so it may also be primarily regional. From what I've seen so far, the folks in the PNW don't have as much of an issue.

Same, but if you think about it it makes sense. The charging curve is pretty conservative relative to the pack size, relative to the overall capacity it's not pushing that much current. That's at least how I'm looking at it.

I was actually not aware EA had any 500 amp chargers in their fleet. I'd be interested in seeing what model works and its dataplate.

 

[rhuber]

I don't know how many times to repeat this, but I've charged my 400-ish volt Tesla at 500 amps at a number of EA chargers, including ABB ones. Rivians not charging at 500A at some stations isn't a simple EA only issue. There is some interaction between the trucks and some stations that leads to them capping at 350A.

In a practical sense I understand that it basically doesn't matter "why", but I'm trying to point out that this is probably a combination of factors involving both rivian and the station hardware in some cases not doing the right thing. Blaming it solely on EA ignores the fact that I've literally used these stations at 500 amps, so there is something more complicated at play here.

 

[SeaGeo]

I don't know how many times to repeat this, but I've charged my 400-ish volt Tesla at 500 amps at a number of EA chargers, including ABB ones. Rivians not charging at 500A at some stations isn't a simple EA only issue. There is some interaction between the trucks and some stations that leads to them capping at 350A.

In a practical sense I understand that it basically doesn't matter "why", but I'm trying to point out that this is probably a combination of factors involving both rivian and the station hardware in some cases not doing the right thing. Blaming it solely on EA ignores the fact that I've literally used these stations at 500 amps, so there is something more complicated at play here.

Good point and thanks for reminding folks explicitly. That's why I've been hesitant to just say it's all or only ABB hardware having heard you didn't experience it consistently.

It's interesting that Kyle ran into the issue on both the R1T and EQS.

 

[rhuber]

Good point and thanks for reminding folks explicitly. That's why I've been hesitant to just say it's all or only ABB hardware having heard you didn't experience it consistently.

It's interesting that Kyle ran into the issue on both the R1T and EQS.

Yeah, I totally agree, and look forward to the side-by-side testing of a tesla+ccs adapter and my rivian, because I think it will illustrate that the problem isn't so simple.

CCS is such an overwrought and complicated protocol, that it could be any number of fun edge cases causing this issue.

 

[SANZC02]

I don't know how many times to repeat this, but I've charged my 400-ish volt Tesla at 500 amps at a number of EA chargers, including ABB ones. Rivians not charging at 500A at some stations isn't a simple EA only issue. There is some interaction between the trucks and some stations that leads to them capping at 350A.

In a practical sense I understand that it basically doesn't matter "why", but I'm trying to point out that this is probably a combination of factors involving both rivian and the station hardware in some cases not doing the right thing. Blaming it solely on EA ignores the fact that I've literally used these stations at 500 amps, so there is something more complicated at play here.

Can you share what CCS toTesla adapter you are using? I have been looking for a good one but have not seen one rated for 500 amps.

 

[rhuber]

Can you share what CCS toTesla adapter you are using? I have been looking for a good one but have not seen one rated for 500 amps.

It was from evhub.shop - I helped them debug some issues with it, actually. Unfortunately, they are based in Ukraine and production is completely stopped for obvious reasons.

And yes it says "400A" in the description, but the fine print says "Rated for 400A(allowed up to 600A peaks at 5-40%SoC) 400V making it 160kW" and I independently verified temperatures are completely fine, even at 500A for multiple minutes.

 

[SANZC02]

It was from evhub.shop - I helped them debug some issues with it, actually. Unfortunately, they are based in Ukraine and production is completely stopped for obvious reasons.

And yes it says "400A" in the description, but the fine print says "Rated for 400A(allowed up to 600A peaks at 5-40%SoC) 400V making it 160kW" and I independently verified temperatures are completely fine, even at 500A for multiple minutes.

Thanks, I’ll check it out.

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