Lucid's Charging Curve, can it be improved via OTA update?

[rfc805]

In this case it actually has nothing to do with voltage (well, it does, but in a different way), but just a matter of C rate. Temperature is relevant, but there's no temperature which prevents it, there's just an ideal temperature which makes it least likely. Which is what pre-conditioning does for us. Thermally there's little difference between doing 200kW at 400v and 800v, it's still 200kW and you're probably losing like 10% of that 200kW to heat or somewhere around that, regardless of voltage. Voltage does let you do 200kW with thinner conductors as you mentioned, but the heat loss is still essentially the same. It just lets you put more cooling material in the same space where the smaller conductor now is. If you were already meeting your thermals with the 400V conductors, it won't matter though.

He explains it better than I can, but there is no magic solution. Even with perfect thermals, if you charge at a high C rate even at 70-80% SoC, you will (probably) degrade the battery significantly. It's worth a watch.

 

[BS8899]

In this case it actually has nothing to do with voltage (well, it does, but in a different way), but just a matter of C rate. Temperature is relevant, but there's no temperature which prevents it, there's just an ideal temperature which makes it least likely. Which is what pre-conditioning does for us.

He explains it better than I can, but there is no magic solution. Even with perfect thermals, if you charge at a high C rate even at 70-80% SoC, you will (probably) degrade the battery significantly. It's worth a watch.

It is more than temperature. Oxidation/reduction processes are accelerated (or retarded) by temperature (thermodynamics). But remember, oxidation/reduction (plating/erosion) is about gaining/losing electrons, hence the voltage.

 

[rfc805]

Yes, but in this case, the plating effect is actually a secondary effect, not a primary effect. The transfer of li-ion is intentional in this case, not an erosion effect, but the actual battery chemistry. The problem is when the overall rate is too high, they "miss" their intended target and plate the conductor instead. That's part of why it's a probability versus a certainty - if it were just like electro plating, it'd be a guaranteed result, but this isn't that, it's battery chemistry, where you're doing a very similar thing, but with an intended target of graphite material.

But seriously - try his video, because I'm not doing anywhere near as good a job as he does.

 

[BS8899]

Yes, but in this case, the plating effect is actually a secondary effect, not a primary effect. The transfer of li-ion is intentional in this case, not an erosion effect, but the actual battery chemistry. The problem is when the overall rate is too high, they "miss" their intended target and plate the conductor instead. That's part of why it's a probability versus a certainty - if it were just like electro plating, it'd be a guaranteed result, but this isn't that, it's battery chemistry, where you're doing a very similar thing, but with an intended target of graphite material.

But seriously - try his video, because I'm not doing anywhere near as good a job as he does.

I watched the video. I don't disagree with the contents. The author looked at extreme ranges of temperature and charging rates in order to elucidate/exaggerate the degradation mechanisms. This is helpful in understanding the mechanisms. That said, it is not just about temperature. There is an electrochemical process at play simultaneously. A simple way to think about it is to think back to your high school chemistry demonstration of electrolysis of water. The author was using extremely conditions (e.g., 10X over SoC limit) to illustrate the adverse mechanisms at play.

However, I think we are talking pass each other. We are talking about a much narrower range of parameters:
> we follow the manufacturer's directions. No one is advocating to continuously overcharging the battery.
> we follow the directions for preconditioning.
> when I charge my car to 100% SOC, I only do that hours before I depart on the 1st leg of my road trip.
> other than on long road trips, I only charge to 80% SoC.
> My EVs are not charged to 100% SoC and left sitting at 50 degree C for any length of time.

The original question I posed in his tread was whether there is a better way to optimize the charging/discharging curve on the Lucid while not exceeding the manufacturer's recommended specs.

 

[Boomer AZ]

My 2022 AGT, seems to be charging a little faster. A bit faster rate at higher SOC. SOC: 17% to 80%. 65°F air temperature. Battery preconditioned.

73.85 kWh from EA
38 minutes

My long drive is Prescott, AZ to Redondo Beach, CA. I’ve made it there on 1 charge, sucking electrons at the end. Must recharge on the return trip due to 5800’ elevation increase. Charge at Quartzite or Blythe. If Quartzite EA is full, use ChargePoint in Blythe. 62.5/125 kW charger at Denny’s.

I always wish for a faster recharge, but my expectations are quickly dropping.

 

[rfc805]

Interesting - so Kyle in their latest EV race video provided something which maybe explains our differences. Apparently Lucid has some sort of counter + algorithm around DC fast charging. It de-rates DC charging performance based on some sort of ratio of how many times you have recently DC fast charged vs AC L2 charged. So if you're seeing poor DC charging speeds, story might be you need to spend some time AC charging.

 

[Buffalo Bob]

Interesting - so Kyle in their latest EV race video provided something which maybe explains our differences. Apparently Lucid has some sort of counter + algorithm around DC fast charging. It de-rates DC charging performance based on some sort of ratio of how many times you have recently DC fast charged vs AC L2 charged. So if you're seeing poor DC charging speeds, story might be you need to spend some time AC charging.

Seems like an odd dynamic going on in the forum the last few days. The above bombshell (if indeed correct) gets dropped 24 hours ago, and not a word is said about it one way or another. @Joe posted Car & Drivers stellar ranking of the 2025 Air as the best luxury electric car 22 hours ago, and 'thud'. Yet, the same old tired threads persist ad nauseum. I'm confused.

 

[Lucken]

Seems like an odd dynamic going on in the forum the last few days. The above bombshell (if indeed correct) gets dropped 24 hours ago, and not a word is said about it one way or another. @Joe posted Car & Drivers stellar ranking of the 2025 Air as the best luxury electric car 22 hours ago, and 'thud'. Yet, the same old tired threads persist ad nauseum. I'm confused.

It would be great if we could get some kind of confirmation from Lucid that such a charging algorithm actually exists. I seem to recall a similar rumor in the BMW forum regarding the i4, but that too was conjecture and never confirmed. At this point I’m not assuming it to be fact.

 

[tonybot]

Interesting - so Kyle in their latest EV race video provided something which maybe explains our differences. Apparently Lucid has some sort of counter + algorithm around DC fast charging. It de-rates DC charging performance based on some sort of ratio of how many times you have recently DC fast charged vs AC L2 charged. So if you're seeing poor DC charging speeds, story might be you need to spend some time AC charging.

I saw that as well and it was news to me. Are folks aware of what this is and how it is calculated? Is it just the number of times AC charging was done versus amount of energy delivered over AC vs DC? It would be great to get some clarity from people in the know such as @mcr16 .

 

[BS8899]

I saw that as well and it was news to me. Are folks aware of what this is and how it is calculated? Is it just the number of times AC charging was done versus amount of energy delivered over AC vs DC? It would be great to get some clarity from people in the know such as @mcr16 .

At the risk of stating the obvious....car Li batteries are only charged with DC. Thus, the only difference between Home AC charging (8kW-18kW) vs DCFC (up to 350kW) is the rate of charge. If the quote on what Kyle said is true, it suggests that Lucid's "algorithm" is based on a "short-hand" DC vs AC charging times? That seems like a lame approach!

Someone far more knowledgeable than I can correct my misconceptions:

> Below 80% SoC, the voltages on the electrodes are relatively safe RE: long-term degradation. Defects in the electrode is a separate factor.
> charging (regularly) to 100% and maintaining the SoC at that level results in (slightly) higher electrode voltage at the battery, which promotes electrode erosion.
> prolonged high temperature storage/exposure is undesirable due to thermodynamics.
> dendrite growth and plating, which causes long-term battery degradation, are mostly "defect" accelerated. Sharp geometries in the electrodes (e.g., imperfects, nicks, etc.) create high electric fields hence acceleration of dendrites/corrosion.

When a battery pack degrades over time, it is often caused by a few "weak cells" (as opposed to a general degradation of the entire pack) which, if the weak cells were replaced, can restore the health of the battery pack. The challenge herein is having the service infrastructure to do this kind of repair.

Thoughts?

 

[levsha]

Sure, what's the 10 year degradation on the battery packs for the cars doing 200kW sustained?

Answer: We don't know, they haven't existed that long.

Better isn't just about the short term. Subjectively to you, that matters more.

And what is the 10 year degradation for Lucid Air battery on its charging curve?
The answer is: we don't know either, they haven't existed that long.

Everyone does estimations based on various intensive stress-tests. And not only car manufacturers: battery manufacturers do this as well or even more. Everyone provides warranty on the battery these days. Assuming Lucid has done that better than let's say Hyundai is pure speculation if it is done without any objective data.

 

[borski]

I’m just gonna go ahead and not rely on random statements in YouTube videos by people who don’t work for Lucid, extremely tired, on a very long drive.

Y’all speculate all you want. I’m just not gonna bother worrying about it because it won’t change how I charge at all (even if I could optimize it somehow), and until Lucid confirms (which I’m extremely curious about!) I think this is one guessing game I’ll respectfully bow out of.

Have fun.

 

[levsha]

I’m just not gonna bother worrying about it because it won’t change how I charge at all (even if I could optimize it somehow), and until Lucid confirms (which I’m extremely curious about!) I think this is one guessing game I’ll respectfully bow out of.

And that is what I've seen quite a few times already in various videos containing extensive explanations of what happens inside of the battery: "don't overcomplicate things, especially at cost of your convenience - use your car how would you use it, just try to avoid extreme cases if possible"