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

[BS8899]

Inasmuch as Lucid touts its 900V architecture and fast charging, it is apparent that many studies have concluded that the fast charging is only beneficial in the initial 5-8min, if the SoC is low (say 10% or less). With the current DCFC, the rate of fast charging is not sustained. Various studies (OoS, SoC, etc.) have shown that competitor's vehicles with a flatter, sustained charging rate is much more beneficial in replenishing charge on road trips. I have done many long road trips on my AGT and my experience validate these concerns.

Q: can Lucid "rebalance" its charging curve via OTA on the Wunderbox?

 

[hydbob]

They have already

 

[rfc805]

"Improved" is a difficult word, because it's subjective.

Charging is a balance of a lot of factors, thermal, longevity, etc. I only know of one competitor who has presumably a better curve for road trips, which is the Taycan.

The question that is unknown is the long term effect of the difference of this curve. Lucid could change it today and just make it absolutely rip - but battery degradation over the next 5 years might be absolutely awful as a result.

Have to kind of trust that they're adjusting it the best they can for a much longer battery lifespan - probably at least 10 years. We won't know for quite a while the outcome of the charging curves on the Taycan and Ioniq, etc. We do know long term on the Tesla at this point, and it's probably telling that the actual energy intake rate of the Lucid is very similar to Tesla.


Personally, for me - I presume this is triggered by Out of Spec's recent test. I don't find a 20 or 25 minute stop to be meaningfully different than a 15 minute stop. Especially after 200 miles of driving. The car charges faster to go further than my body wants to. I grab some food and a drink/coffee on the way to the charger, then I plug in and eat/drink stretch/walk/bathroom/etc. So far each time the car has been at least 5-10% past my target by the time I'm done doing all of this.

If I were doing say a 1200 mile trip, stopping every 200 miles or so, that's 6 stops maybe. Adding an extra 5-10 minutes per stop, that's an extra 30-60 minutes for the total trip. An 18 hour trip turning into an 18h30 or 19h is probably less delay than I'm going to deal with in total from traffic/weather/etc anyhow. Best to just enjoy the trip and not worry about it.

 

[BS8899]

They have already

Do you have the charging curve profile (before/after)?

I haven't seen any tangible improvements in my charging sessions.

 

[BS8899]

"Improved" is a difficult word, because it's subjective.

Charging is a balance of a lot of factors, thermal, longevity, etc. I only know of one competitor who has presumably a better curve for road trips, which is the Taycan.

The question that is unknown is the long term effect of the difference of this curve. Lucid could change it today and just make it absolutely rip - but battery degradation over the next 5 years might be absolutely awful as a result.

Have to kind of trust that they're adjusting it the best they can for a much longer battery lifespan - probably at least 10 years. We won't know for quite a while the outcome of the charging curves on the Taycan and Ioniq, etc. We do know long term on the Tesla at this point, and it's probably telling that the actual energy intake rate of the Lucid is very similar to Tesla.

Ummm, Lucid's claim is their "industry-leading" fast charge, @350+kW, 900V etc.. Other competitors are doing much better with flatter charging curves that imports 200kW over a sustained period of time (say 30min). Lucid's charge rates often dropped well below the 200kW level after10m.

 

[rfc805]

Ummm, Lucid's claim is their "industry-leading" fast charge, @350+kW, 900V etc.. Other competitors are doing much better with flatter charging curves that imports 200kW over a sustained period of time (say 30min). Lucid's charge rates often dropped well below the 200kW level after10m.

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.

 

[Pragmatic]

Lucid does not claim to have the fastest charging on a kw-hr basis. They claim to have the fastest charging on a miles gained per minute basis. So if a Taycan can get 75 kw-hr in 15 minutes while the Lucid gets 60 in the same 15 minutes, the Taycan would go 225 miles on the 75 kw-hr charge while the Lucid would go 230 miles.

NOTE: All the numbers I used were for illustrative purposes and do not reflect Lucid or Porsche actual charging rates or efficiencies.

 

[BS8899]

Lucid does not claim to have the fastest charging on a kw-hr basis. They claim to have the fastest charging on a miles gained per minute basis. So if a Taycan can get 75 kw-hr in 15 minutes while the Lucid gets 60 in the same 15 minutes, the Taycan would go 225 miles on the 75 kw-hr charge while the Lucid would go 230 miles.

NOTE: All the numbers I used were for illustrative purposes and do not reflect Lucid or Porsche actual charging rates or efficiencies.

Understood!

I do a fair amount of long distance (780 miles each way) travelling between AZ and CA. I rotate between my Lucid AGT and my Rivian R1S. The Lucid is 900V architecture, but the charging curve drops off precipitously after the first 5-7 min. This, in combination with the flaky EA chargers, makes the Lucid taking on LESS charge/miles in the first 30min of charging, which is the key on road trips.

In contrast, my R1S charges at 400V. I charge at the Rivian Adventure Charging Stations (300kW chargers). Even though the Rivian is less efficient than the Lucid (~2.6m/kWh), most of the time, I can on-board more miles in 30min than with the Lucid on EA. The Rivian chargers are very reliable and delivers sustained 150+kW most of the way to ~80% SoC.

Yes, I know part of the problem is EA. In reality, when it comes to charging for 30-40min on the Lucid (say, starting w/ 10% SoC), there is virtually no differences between the EA 150kV and 300kV chargers. By the time you get to 50%+, the charge rate is often less than 80kW.

I understand the limiters of thermal and battery degradation. But I think a flatter charging curve is more advantageous for road tripping.

 

[Buffalo Bob]

I think it would be nice to have a 'max rate' charging option, similar to that choice on our A/C panel. The standard then being the more conservative (longer battery life) curve, with the option to flatten the curve when you feel the need to do so. Perhaps implementing this would be more technologically demanding than I'm imagining. If I had only one option, I would prefer the current trade-off between charging time and battery life, but I could see where others would prefer the exact opposite.

 

[Rogue]

Understood!

I do a fair amount of long distance (780 miles each way) travelling between AZ and CA. I rotate between my Lucid AGT and my Rivian R1S. The Lucid is 900V architecture, but the charging curve drops off precipitously after the first 5-7 min. This, in combination with the flaky EA chargers, makes the Lucid taking on LESS charge/miles in the first 30min of charging, which is the key on road trips.

In contrast, my R1S charges at 400V. I charge at the Rivian Adventure Charging Stations (300kW chargers). Even though the Rivian is less efficient than the Lucid (~2.6m/kWh), most of the time, I can on-board more miles in 30min than with the Lucid on EA. The Rivian chargers are very reliable and delivers sustained 150+kW most of the way to ~80% SoC.

Yes, I know part of the problem is EA. In reality, when it comes to charging for 30-40min on the Lucid (say, starting w/ 10% SoC), there is virtually no differences between the EA 150kV and 300kV chargers. By the time you get to 50%+, the charge rate is often less than 80kW.

I understand the limiters of thermal and battery degradation. But I think a flatter charging curve is more advantageous for road tripping.

My GT-P charges at 145-155kW up to 72%. I believe only the GT-P and DE do this. However, 2025 models should have similar charging curves.

 

[BS8899]

Understood!

I do a fair amount of long distance (780 miles each way) travelling between AZ and CA. I rotate between my Lucid AGT and my Rivian R1S. The Lucid is 900V architecture, but the charging curve drops off precipitously after the first 5-7 min. This, in combination with the flaky EA chargers, makes the Lucid taking on LESS charge/miles in the first 30min of charging, which is the key on road trips.

In contrast, my R1S charges at 400V. I charge at the Rivian Adventure Charging Stations (300kW chargers). Even though the Rivian is less efficient than the Lucid (~2.6m/kWh), most of the time, I can on-board more miles in 30min than with the Lucid on EA. The Rivian chargers are very reliable and delivers sustained 150+kW most of the way to ~80% SoC.

Yes, I know part of the problem is EA. In reality, when it comes to charging for 30-40min on the Lucid (say, starting w/ 10% SoC), there is virtually no differences between the EA 150kV and 300kV chargers. By the time you get to 50%+, the charge rate is often less than 80kW.

I understand the limiters of thermal and battery degradation. But I think a flatter charging curve is more advantageous for road tripping.

The other thing that eludes me is:
> Lucid's 900V charging architecture should substantially reduce the charge current hence, the thermal heating (I**2R) (for the same kWh delivered). If so, why wouldn't Lucid be able to sustain a flatter (longer) charging curve compared to competitors charging at 400V?

Can someone educate us all on what's missing?

 

[sdlucid]

I think it would be nice to have a 'max rate' charging option, similar to that choice on our A/C panel. The standard then being the more conservative (longer battery life) curve, with the option to flatten the curve when you feel the need to do so. Perhaps implementing this would be more technologically demanding than I'm imagining. If I had only one option, I would prefer the current trade-off between charging time and battery life, but I could see where others would prefer the exact opposite.

I was having a similar thought. If longevity is the main concern for Lucid to reduce charging speed, they should offer customers a limited number of 'max rate' mode that they can use - say 10 times a year or so. This will help us plan the trips accordingly. For eg: If I am just doing a restroom break, I would use this max rate mode, but if I am planning to have some food, I can manage with the slower curve.

 

[Adnillien]

The other thing that eludes me is:
> Lucid's 900V charging architecture should substantially reduce the charge current hence, the thermal heating (I**2R) (for the same kWh delivered). If so, why wouldn't Lucid be able to sustain a flatter (longer) charging curve compared to competitors charging at 400V?

Can someone educate us all on what's missing?

It is true that the Lucid 900V architecture will have lower current and therefor lower IR loss, but that really only helps the components outside of the battery. I say this because if you think about two batteries of the same size where one is 400V and one is 800V. Both batteries have the same number of cells, the difference is the 400V battery has twice as many shorter strings in parallel than the 800V battery. Hence, the current to each cell at the same power is the same between 400V and 800V batteries and the resistive heating within the batteries is the same.

From the tech talks, we know the Air has a 10kW medium power inverter that primarily powers battery cooling, drive train cooling and cabin cooling. The capacity of this cooling system will also limit the charge rate. When talking about the Taycan, Out of Spec said that it had 20kW available for cooling and this is one of the reasons that it can charge so rapidly.

 

[Bus Driver]

It is true that the Lucid 900V architecture will have lower current and therefor lower IR loss, but that really only helps the components outside of the battery. I say this because if you think about two batteries of the same size where one is 400V and one is 800V. Both batteries have the same number of cells, the difference is the 400V battery has twice as many shorter strings in parallel than the 800V battery. Hence, the current to each cell at the same power is the same between 400V and 800V batteries and the resistive heating within the batteries is the same.

From the tech talks, we know the Air has a 10kW medium power inverter that primarily powers battery cooling, drive train cooling and cabin cooling. The capacity of this cooling system will also limit the charge rate. When talking about the Taycan, Out of Spec said that it had 20kW available for cooling and this is one of the reasons that it can charge so rapidly.

Wow. Had to read it twice, not because of your writing, but because of my comprehension. There’s a reason I never became a lawyer. Very informative. Thank you.

 

[BS8899]

It is true that the Lucid 900V architecture will have lower current and therefor lower IR loss, but that really only helps the components outside of the battery. I say this because if you think about two batteries of the same size where one is 400V and one is 800V. Both batteries have the same number of cells, the difference is the 400V battery has twice as many shorter strings in parallel than the 800V battery. Hence, the current to each cell at the same power is the same between 400V and 800V batteries and the resistive heating within the batteries is the same.

From the tech talks, we know the Air has a 10kW medium power inverter that primarily powers battery cooling, drive train cooling and cabin cooling. The capacity of this cooling system will also limit the charge rate. When talking about the Taycan, Out of Spec said that it had 20kW available for cooling and this is one of the reasons that it can charge so rapidly.

Agree with your explanation RE: the battery self-heating during charging is the same, as long as the charge rate is the same. Thus, it calls into question:
> If the self-heating of the battery and other degradations that affect battery life (e.g., cell electrode erosion/dendrites) are mostly determined by charging/discharging processes, why a 900V architecture make sense since it mostly benefits the bus bars and wiring harness but not the batteries, correct?
> by the same argument, why can other EVs maintain a flatter charging curve than Lucid?

 

[rfc805]

Understood!

I do a fair amount of long distance (780 miles each way) travelling between AZ and CA. I rotate between my Lucid AGT and my Rivian R1S. The Lucid is 900V architecture, but the charging curve drops off precipitously after the first 5-7 min. This, in combination with the flaky EA chargers, makes the Lucid taking on LESS charge/miles in the first 30min of charging, which is the key on road trips.

In contrast, my R1S charges at 400V. I charge at the Rivian Adventure Charging Stations (300kW chargers). Even though the Rivian is less efficient than the Lucid (~2.6m/kWh), most of the time, I can on-board more miles in 30min than with the Lucid on EA. The Rivian chargers are very reliable and delivers sustained 150+kW most of the way to ~80% SoC.

Yes, I know part of the problem is EA. In reality, when it comes to charging for 30-40min on the Lucid (say, starting w/ 10% SoC), there is virtually no differences between the EA 150kV and 300kV chargers. By the time you get to 50%+, the charge rate is often less than 80kW.

I understand the limiters of thermal and battery degradation. But I think a flatter charging curve is more advantageous for road tripping.

This doesn't sound right. Recently did a trip between Chicago and St. Louis, which is ~350 miles each way. 2.6m/kWh is very optimistic for an R1S - are you sure this is true?

I was still seeing ~160kW at 75% in the Lucid. I think it did drop to ~120kW around 80%.

I just checked my app, it was 64 kWh in 26 minutes. I think that math works out to an average of 147kW over the session. But on the trip even on the 20" sport tires I was at 3.7 mi/kWh. I don't see how the R1S could be getting more mileage out of this?

If we assume over 30 minutes it would've dropped to a 140kW average, that'd be 70 kWh @ 3.7mi/kWh, that's 259 miles.
(on the return trip, I did 51.2 kWh in 19 minutes, which is closer to 160kW average)
If the Rivian holds 150kW the entire time (given their fame for thermal issues while DC fast charging, that's optimistic), it would only take on 75kWh, even @ 2.6mi/kWh that's 195 miles.

 

[BS8899]

This doesn't sound right. Recently did a trip between Chicago and St. Louis, which is ~350 miles each way. 2.6m/kWh is very optimistic for an R1S - are you sure this is true?

I was still seeing ~160kW at 75% in the Lucid. I think it did drop to ~120kW around 80%.

I just checked my app, it was 64 kWh in 26 minutes. I think that math works out to an average of 147kW over the session. But on the trip even on the 20" sport tires I was at 3.7 mi/kWh. I don't see how the R1S could be getting more mileage out of this?

If we assume over 30 minutes it would've dropped to a 140kW average, that'd be 70 kWh @ 3.7mi/kWh, that's 259 miles.
(on the return trip, I did 51.2 kWh in 19 minutes, which is closer to 160kW average)
If the Rivian holds 150kW the entire time (given their fame for thermal issues while DC fast charging, that's optimistic), it would only take on 75kWh, even @ 2.6mi/kWh that's 195 miles.

My R1S is quad motor. When I am on the interstate, I put it in "Conserve Mode" which turns it into a FWD vehicle. And I drive the speed limit (65-70 mph on CA hwys). Yes, you can get 2.6 miles/kWh. Not sure what the disconnect is...you said your Lucid achieves 3.7m/kWh. That's my experience as well on my Lucid AGT. Lucid's claimed (EPA) efficiency is ~4.6 m/kWh on the AGT. If you read the survey on this forum, most people achieve 3.5-3.7m/kWh.

My R1S has the large pack battery (not the MAX pack). I believe it is 135kWh. Thus, @ 2.6 m/kWh, it should cover 351 miles. In reality (i.e., real driving on the freeway, not just a flat road with ideal temperature), I can drive my R1S cover ~300 miles on a full charge (I-10/I-5).

The Rivian is less efficient, hence 2.6m/kWh. On highway driving (to the speed limit), if you drive conservatively (AKA in accordance with the speed limit), the Rivian routinely exceeds the rated efficiency. On the other hand, Lucid is almost always below its rated efficiency. This is well documented by many reviewers.

 

[rfc805]

I know they can do 2.6 mi/kWh - but my experience with them has been over long road trips, reality is closer to 2.2 on the Gen1 Quads. Other people I know with the Gen1 quads seem to be more in the 2.1-2.4 - you certainly can get 2.6, just unusual to average it.

But that isn't the part that I was arguing - you said the Rivian was putting in more range in the same amount of time, which the more important part is at the bottom of what you quoted. That shouldn't be true at all, not even close.

 

[BS8899]

I know they can do 2.6 mi/kWh - but my experience with them has been over long road trips, reality is closer to 2.2 on the Gen1 Quads. Other people I know with the Gen1 quads seem to be more in the 2.1-2.4 - you certainly can get 2.6, just unusual to average it.

But that isn't the part that I was arguing - you said the Rivian was putting in more range in the same amount of time, which the more important part is at the bottom of what you quoted. That shouldn't be true at all, not even close.

Read my earlier posting on this tread. I explicitly said that part of the Lucid charging problem might be EA chargers. I charge on Rivian on Rivian Adventure Chargers. The Rivian chargers are 300 kW...and they deliver reliably to mid to high 200 kW range at low SoC and mostly sustain to >150kW up to ~80% SoC. I have never come across an EA charger (where I charge my Lucid) that delivers this level of power consistently.

 

[koflo]

Too many factors involved when it comes to calculating the efficiency of both vehicles honestly. My Air DE-P during the summer months in AZ averaged out a 2.9m/kwh over 3000 miles roughly. My other EV handles the summer heat much better and had an average efficiency of 2.8m/kwh.

Another anecdote, I took the Air to Vegas this past weekend. Temperatures dropped lower than expected this past week in Vegas and AZ. That mixed with elevation changes tanked my efficiency for the whole trip (where I used cruise control 90% of the time) right around 3 m/kwh.

My point being that if we are comparing efficiency numbers, we would have to run both cars in the same exact environment with the same external factors. That's why EPA exists. Another good thought provoking idea is the idea that more efficient cars get range hit more when they are less efficient. In Lucid's case, their EPA numbers are very high m/kwh but also means that they suffer more from an overall mileage perspective with outside factors.

Im all for sustained higher rates as long as the customer has to accept the potential longevity issues.