DC Throttling "battery conditioning"

[plasmdude]

I got a battery conditioning message in LA last week. It was about 100F that day and was charging using a EA 500A charger. I was only getting 125kw. I forgot to take a picture of the charge but the roll back was occurring about at the 80% SoC drop off and so did not get that much slowdown. I think the battery pack was warm and was cooling. Could hear lots of fans going on under the hood.

It would be nice to have more stats info about various component temps on the dashboard. Also same info in the mobile app.

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[plasmdude]

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

You can find a specifications plate/sticker if you look around the back side of the chargers maybe near the ground. It will say the rated input/output voltages and amperages. I have seen a few that have not weathered very well and are fading and pealing off.

 

[ajdelange]

I think a lot of confusion stems from the fact that people seem to think that the OEMs try to design to a "charge curve". In fact they have an elaborate set of rules that determine allowable charge rate as a function of several variable such as SoC and temperature (which are probably the most important). Starting from low SoC at ideal temperature the battery may be allowed to charge at >1C. If it is cold, as you have all seen, the allowable rate will be <1C. As the battery warms the allowable rate is increased. Thus an obvious strategy for loading charge faster at low SoC in cold weather is to warm it. Of course the battery warms itself when it charges but that doesn't preclude the use of resistive heaters, heat pumps, setting the inverters to low efficiency if pre-conditioning on the way to the charger is implemened etc.

In any case the rule set and the charging conditions determine the charge profile realized as a function of SoC and of time. "Improving" the charge curve must come from making more heat available (cold weather) or enhanced heat removal (hot) or by making the rule set less strict.

 

[SeaGeo]

You can find a specifications plate/sticker if you look around the back side of the chargers maybe near the ground. It will say the rated input/output voltages and amperages. I have seen a few that have not weathered very well and are fading and pealing off.

That won't help. The ABB chargers that are the problem are supposed to be able to output 500A.

 

[SeaGeo]

I think a lot of confusion stems from the fact that people seem to think that the OEMs try to design to a "charge curve". In fact they have an elaborate set of rules that determine allowable charge rate as a function of several variable such as SoC and temperature (which are probably the most important). Starting from low SoC at ideal temperature the battery may be allowed to charge at >1C. If it is cold, as you have all seen, the allowable rate will be <1C. As the battery warms the allowable rate is increased. Thus an obvious strategy for loading charge faster at low SoC in cold weather is to warm it. Of course the battery warms itself when it charges but that doesn't preclude the use of resistive heaters, heat pumps, setting the inverters to low efficiency if pre-conditioning on the way to the charger is implemened etc.

In any case the rule set and the charging conditions determine the charge profile realized as a function of SoC and of time. "Improving" the charge curve must come from making more heat available (cold weather) or enhanced heat removal (hot) or by making the rule set less strict.

I think most people realize that. The Rivian just doesn't do a particularly great job if saying "why" all the time, and the behavior is a bit different than people typically see. For example, it pulls nearly 200 and then will battery conditioning and throttle because it's still tool cold as it increases SOC. Or at least that was the original problem.

And then the ABB chargers just not providing more than 350A was a little confusing for folks.

 

[zefram47]

I think most people realize that. The Rivian just doesn't do a particularly great job if saying "why" all the time, and the behavior is a bit different than people typically see. For example, it pulls nearly 200 and then will battery conditioning and throttle because it's still tool cold as it increases SOC. Or at least that was the original problem.

And then the ABB chargers just not providing more than 350A was a little confusing for folks.

It just seems like Rivian has the conditioning set to trigger at some temperature rather than intercepting the ramping temperature and preemptively ramping up the cooling to keep things in check. But who knows unless you're inside Rivian.

As for the ABB 350A limit, I looked up a spec sheet for their chargers. I was surprised to see they only claim 375A on the 350 kW capable chargers with a single power cabinet. Those units only claim 500A when in a dual power cabinet configuration such that both handles could be used simultaneously. So it seems like the issue is that they are being installed in single cabinet configuration and not double, so it's not a software limitation. I wonder if that means they might upgrade them in the future, but I kinda doubt it. EA probably assumes that most cars will go 800V in the near future so they don't care.

https://www.evchargesolutions.com/v/downloads/ABB-TerraHP-UL-G2.pdf

 

[SeaGeo]

It just seems like Rivian has the conditioning set to trigger at some temperature rather than intercepting the ramping temperature and preemptively ramping up the cooling to keep things in check. But who knows unless you're inside Rivian.

As for the ABB 350A limit, I looked up a spec sheet for their chargers. I was surprised to see they only claim 375A on the 350 kW capable chargers with a single power cabinet. Those units only claim 500A when in a dual power cabinet configuration such that both handles could be used simultaneously. So it seems like the issue is that they are being installed in single cabinet configuration and not double, so it's not a software limitation. I wonder if that means they might upgrade them in the future, but I kinda doubt it. EA probably assumes that most cars will go 800V in the near future so they don't care.

https://www.evchargesolutions.com/v/downloads/ABB-TerraHP-UL-G2.pdf

Good find. I hadn't noticed that when I was looking at their spec last time. That's going to limit some "800v" vehicles as well (like the hummer). They'd be squeaking by at 345kw @ 375A x 920v. I don't believe the Hummer is anywhere close to 920V. Between the iX, EQS, R1T, R1S, and Hummer just off the top of my head they're going to frustrate a bunch of people. Hopefully EA at least clarifies which chargers are limited to 375A in a way that's obvious somehow.

 

[zefram47]

Good find. I hadn't noticed that when I was looking at their spec last time. That's going to limit some "800v" vehicles as well (like the hummer). They'd be squeaking by at 345kw @ 375A x 920v. I don't believe the Hummer is anywhere close to 920V. Between the iX, EQS, R1T, R1S, and Hummer just off the top of my head they're going to frustrate a bunch of people. Hopefully EA at least clarifies which chargers are limited to 375A in a way that's obvious somehow.

There is still another issue though. Recall Kyle used a charger that Ryan had gotten 500A out of and was still limited to 350A, so there's something else at play. But even Kyle and TFL's Hummer reviews noted only around 240 kW at an ABB station vs the 300+ kW that was expected. IIRC, Hummer is ~350V parallel and ~700V in series for charging...so that's part of the issue. 700V at 350A is 245 kW.

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