Charging curve logs post 2.1.52

[HariK]

I collected charging curve data long ago and since then my observation at EA is that with lucid pure 92kwh battery whether it is 350kw or 150kw 30% to 80% average was not much better than 1.5kwh per min which in my case is about 5.5 miles per min at 3.7 miles per KWh. In a long distance trip I personally want a 15 min break every 2hrs which is about 130 miles at 70mph HA cruise. That takes 35 min currently to top off 130 miles at average EA. Best case is 2kwh per min is 17min at a good EA. Pre conditioning is required on a cold start but once on the road and the ambient is over 50, I did not see much difference. I will redo my charge curve at the local 350 and 150 EA. It is a tradeoff. Drive fast and take more time at the charger or drive slow and less time at the charger.

 

[Rogue]

I also wanted to compare how this new charging curve log compared to data I've collected previously, and you'll see that chart below. Unfortunately the old data was mostly collected in 5% increments and the new in 1% increments, but you can still hopefully see how they compare. Aside from the increased peak speeds at low battery levels it seems pretty comparable, although the new curve is slightly higher than the old curve starting at about 35%. There was not a significant change in total charging duration, but it's nice to see at least some slight improvements!

View attachment 18649

If you made it this far, thank you very much for reading! I know these comparisons aren't very interesting for most, and that they're of very limited practical use. I just find it really interesting to see how the changes look in a real-world scenario, and I like to know what my car is capable of given the right conditions. I'd be interested to hear your thoughts and experiences since 2.1.52. I'm planning on doing another test at a different EVgo station later this week, and if I find anything interesting I'll make note of it in this thread. Special thanks to @Volund for providing their car and their time. All the best!

As promised @Shane_SLC, here is the data starting at 6% to 92%. The last 8% and 72-90% I was in the store unable to check. The first 6% was impractical to bring lower at the location.

The GT-P appears to end maximal trade-off (in my opinion) once it hits 72% with an aggressive drop in charging rate. 150-155 kWh lasts between 50-72% as a flatline.

Percentage: Start-Stop : kWh: Start, Stop
6-10 : 320 (Step-up from 180 over a few seconds)
10-15 : 320, 300
15-20 : 300, 290
20-25 : 290, 270
25-30 : 270, 250
30-35 : 250, 225
35-40 : 225, 195
40-45 : 195, 170
45-50 : 170, 155
50-55 : 155, 150
55-60 : 150, 155
60-72 : 155, 150
90-91 : 65, 55
91-93 : 55, 50
93+ : Slow Speeds

 

[Lucken]

I haven’t gotten speed curves like that ever, but I guess that’s more a characteristic of the Pure’s charging curve which just isn’t as robust. Good grief, did I just say ‘robust’?

 

[momo3605]

I haven’t gotten speed curves like that ever, but I guess that’s more a characteristic of the Pure’s charging curve which just isn’t as robust. Good grief, did I just say ‘robust’?

The GT-P charging curve is much stronger than the GT which in turn is also significantly stronger than the Pure/Touring. Our charge curve at best is about 2/3 of the GT-P curve. At 70% our curve is at half the rate.

I would be happy if we could have a consistent 92/118 or 78% of the GTP curve. Theoretically it should be this way…but isn’t

 

[Lucken]

The GT-P charging curve is much stronger than the GT which in turn is also significantly stronger than the Pure/Touring. Our charge curve at best is about 2/3 of the GT-P curve. At 70% our curve is at half the rate.

I would be happy if we could have a consistent 92/118 or 78% of the GTP curve. Theoretically it should be this way…but isn’t

What to me is odd is that manufacturers generally implement conservative charging curves to protect the battery. So is Lucid ‘less protective’ of the batteries in the GT as opposed to the Pure or Touring? Admittedly I may be missing things, but is the logic that a higher capacity battery tolerates higher charging rates better at play here? Is the chemistry that much different?

I’m genuinely curious what the engineering logic is.

 

[Adnillien]

The larger battery packs in the GT/GTP have a higher voltage than the packs in Touring and Pure. Fully charged the bigger pack is 924 volts and the smaller packs are 756 volts. Charge rate is primarily limited by current and then to a second order thermal management of the pack. At the same charge current, the bigger pack will charge with 22% more power because of the voltage difference in the pack.

GTP and DE have different battery chemistry so they may also have slightly different charging curves based on what charge current that chemistry can handle.

 

[hmp10]

In a long distance trip I personally want a 15 min break every 2hrs which is about 130 miles at 70mph HA cruise.

Drive fast and take more time at the charger or drive slow and less time at the charger.

My only real aggravation with road trip charging is when we find a station or charge post that is not working properly.

Personally, I detest trying to hyper-mile and consequently drive our Lucid on trips the way I drive ICE cars -- 80-85 mph when traffic allows with occasional bursts to higher speeds to break out of jams and get into open pockets where I try to hold. Driving this way in temperate to hot weather, we usually manage 230-240 miles using 65-70% of the battery capacity in our Dearm P on 21" wheels.

This means charging stops around the 3-hour mark when we can manage it, as that's as long as we want to go without a significant rest break. And even then, we sometimes have to do an interim bathroom break, just as we often did in ICE vehicles between gas stops.

I understand that charging curves and other things related to charge times are legitimately interesting to the techies and truly critical to people who rely on public DCFC for routine charging of their EVs.

But for road-tripping -- and, again, assuming stations that work -- charge times just don't bother me. Whatever time we burn waiting to charge up on a road trip is more than recovered in the visits to gas stations we avoid during the many more weeks of the year we charge at home for daily driving.

 

[Lucken]

The larger battery packs in the GT/GTP have a higher voltage than the packs in Touring and Pure. Fully charged the bigger pack is 924 volts and the smaller packs are 756 volts. Charge rate is primarily limited by current and then to a second order thermal management of the pack. At the same charge current, the bigger pack will charge with 22% more power because of the voltage difference in the pack.

GTP and DE have different battery chemistry so they may also have slightly different charging curves based on what charge current that chemistry can handle.

Thanks for the explanation, makes perfect sense. Now I wonder how much Lucid could loosen up on the charge rates while still not endangering the batteries. I suppose as more miles are racked up by owners, Lucid might be better able to determine that. As an example, my i4 does seem to charge at higher rates at the same set of chargers, at the same SOC, in the same weather conditions and the same battery conditioning. I don't believe the i4's batteries are spec'd at a higher voltage, so perhaps BMW is just a bit less conservative about this.

 

[joec]

The larger battery packs in the GT/GTP have a higher voltage than the packs in Touring and Pure. Fully charged the bigger pack is 924 volts and the smaller packs are 756 volts. Charge rate is primarily limited by current and then to a second order thermal management of the pack. At the same charge current, the bigger pack will charge with 22% more power because of the voltage difference in the pack.

GTP and DE have different battery chemistry so they may also have slightly different charging curves based on what charge current that chemistry can handle.

I was going to respond, but I knew @Adnillien would do a much better job.

 

[momo3605]

The larger battery packs in the GT/GTP have a higher voltage than the packs in Touring and Pure. Fully charged the bigger pack is 924 volts and the smaller packs are 756 volts. Charge rate is primarily limited by current and then to a second order thermal management of the pack. At the same charge current, the bigger pack will charge with 22% more power because of the voltage difference in the pack.

GTP and DE have different battery chemistry so they may also have slightly different charging curves based on what charge current that chemistry can handle.

if the difference was 22% I’d have no issue, because that makes sense.

The issue is that pure/Tourings are getting 40-50% slower rates mid-upper SOC levels

 

[Adnillien]

if the difference was 22% I’d have no issue, because that makes sense.

The issue is that pure/Tourings are getting 40-50% slower rates mid-upper SOC levels

I think you are generalizing your experience to the entire Pure/Touring fleet. I have not seen any data suggesting a 40-50% difference for all Pure/Touring. Given the many times that charging power is limited by the charger so the difference is probably even less than just the voltage difference.

 

[momo3605]

I think you are generalizing your experience to the entire Pure/Touring fleet. I have not seen any data suggesting a 40-50% difference for all Pure/Touring. Given the many times that charging power is limited by the charger so the difference is probably even less than just the voltage difference.

I mean, the data is literally right here in this thread. The GTP is pulling 155kw at 50% where the Pure/Touring pulls 100kw.

At 70%, the GTP is still pulling 150kw and the Pure/Touring pulls 75kw

 

[Adnillien]

I mean, the data is literally right here in this thread. The GTP is pulling 155kw at 50% where the Pure/Touring pulls 100kw.

At 70%, the GTP is still pulling 150kw and the Pure/Touring pulls 75kw

In this thread their is @Shane_SLC data showing the expect 20-25% difference (Chart pasted below, thank you Shane). We have one charge on a GTP and another charge limited by the charger. Not enough data to draw your conclusion.

 

[Bobby]

I mean, the data is literally right here in this thread. The GTP is pulling 155kw at 50% where the Pure/Touring pulls 100kw.

At 70%, the GTP is still pulling 150kw and the Pure/Touring pulls 75kw

Need a much larger sample size to draw conclusions.

 

[momo3605]

Need a much larger sample size to draw conclusions.

Why do you need a larger sample size? The GTP result was not throttled. It's already super fast and 40-50% faster than the Touring. Why would more data give you a different conclusion? We also have multiple Touring curves from Shane, and I've posted a couple too that are consistent.

If another GTP has an even higher result, then the Touring is even more bottlenecked...if another GTP has a lower result, then it is throttled and invalid. So there's no reason to have additional data.

 

[sri]

Why do you need a larger sample size? The GTP result was not throttled. It's already super fast and 40-50% faster than the Touring. Why would more data give you a different conclusion? We also have multiple Touring curves from Shane, and I've posted a couple too that are consistent.

If another GTP has an even higher result, then the Touring is even more bottlenecked...if another GTP has a lower result, then it is throttled and invalid. So there's no reason to have additional data.

To generalize any statement we need to have more samples.
Charging curve on my car is different every time even being on the same location and station.

 

[momo3605]

To generalize any statement we need to have more samples.
Charging curve on my car is different every time even being on the same location and station.

We already know how fast all of these cars will charge. We've seen the fastest charge curves from all the models. I'm sure you have good charging sessions and bad charging sessions, but that doesn't matter, we've seen the unthrottled ones. Anyway, to me it's pretty obvious what the conclusion is, you're welcome to make your own conclusion, I'll bow out here.

 

[Cosmo Cruz]

... with occasional bursts to higher speeds to break out of jams and get into open pockets where I try to hold.

I'm trying to teach the wife this... what I call "surfing the gaps "

But for road-tripping -- and, again, assuming stations that work -- charge times just don't bother me. Whatever time we burn waiting to charge up on a road trip is more than recovered in the visits to gas stations we avoid during the many more weeks of the year we charge at home for daily driving.

home charging: "we few, we happy few"

 

[scal_air]

I haven’t gotten speed curves like that ever, but I guess that’s more a characteristic of the Pure’s charging curve which just isn’t as robust. Good grief, did I just say ‘robust’?

Lucid updates at work I guess?

 

[hydbob]

We already know how fast all of these cars will charge. We've seen the fastest charge curves from all the models. I'm sure you have good charging sessions and bad charging sessions, but that doesn't matter, we've seen the unthrottled ones. Anyway, to me it's pretty obvious what the conclusion is, you're welcome to make your own conclusion, I'll bow out here.

That doesn't make any sense. You claimed that Tourings are throttled. Shane showed you differently. What's the conclusion? Something is wrong with your car or that the chargers near you are throttled? I'm not even sure what you are arguing here when compared to @Rogue charging curve, that @Shane_SLC showed you exactly the dropoff you'd expect based off the difference in battery voltages. There is no grand conspiracy here with Touring/Pure vs GTP/Dream/Sapphire. Physics is physics