Battery Capacity Comparison

[Adnillien]

Since we have discussed battery capacity for Dream versus GT here, it is good to see Lucid Document the 118 kWhr and 112 kWhr capacities. One of the recent reviews talked about Samsung and LG Chem being used on different trims. Does this imply that Samsung is used on the Dream and LG Chem on the GT?

 

[Dortreo]

Since we have discussed battery capacity for Dream versus GT here, it is good to see Lucid Document the 118 kWhr and 112 kWhr capacities. One of the recent reviews talked about Samsung and LG Chem being used on different trims. Does this imply that Samsung is used on the Dream and LG Chem on the GT?

View attachment 174

I posted this in the other forum, but I wonder if there is a difference in capacity between the LG and Samsung cells.

Per the press release, the Dream Edition has a 118kWh battery packs with 22 modules and the GT has a 112kWh battery pack. Each Dream Edition battery pack was 6600 2170 cells made by Samsung SDI, whereas the GT battery packs are supposed to be made from LG Chem cells.

Does this mean that the Dream Edition Samsung SDI cells have a higher wattage than the LG Chem cells? If they both have the same number of cells, a Samsung SDI cell should have 17.9Wh or 4800mAh of storage (assuming 3.7V) and an LG Chem should have 17Wh, or 4600 mAh at 3.7V.

If Lucid had gone with Samsung across the board, the GT could have the same battery pack with 21 modules instead of 22, which would further increase its performance.

 

[Adnillien]

I don't think we can rule out the possibility that the difference in capacity is software and that the choice of battery supplier has to do with thermal performance to enable higher current draw on the Dream edition.

 

[Dortreo]

I don't think we can rule out the possibility that the difference in capacity is software and that the choice of battery supplier has to do with thermal performance to enable higher current draw on the Dream edition.

As a point of reference, the Tesla 2170 battery has 4800 mAh of capacity at 3.7V. I'm sure a lot of factors went into the choice of LG Chem instead of Samsung going forward.

 

[Adnillien]

If Lucid had gone with Samsung across the board, the GT could have the same battery pack with 21 modules instead of 22, which would further increase its performance.

While Lucid could have used fewer cells on the GT it was the same battery cell as the Dream, the kWhr may add up by removing a single module but the series strings of battery cells would not. Lucid is likely using 220 cells in series, 30 strings in parallel for 6600 total cells. They would need to remove either 220 or 440 to keep the same voltage. Since each module has 300 cells, the would have to remove slightly less or slightly more than one module.

 

[WildRide47]

Since we have discussed battery capacity for Dream versus GT here, it is good to see Lucid Document the 118 kWhr and 112 kWhr capacities. One of the recent reviews talked about Samsung and LG Chem being used on different trims. Does this imply that Samsung is used on the Dream and LG Chem on the GT?

View attachment 174

It is nice to see that the GT trim has 819hp(19 more than originally posted) and 885 lb-ft of torque(had not previously been mentioned). Since most of my driving will be in the 0-70 mph range, the acceleration noted above should not be that much different than the Dream Edition Range. Now the question is when will my 1K deposit for the GT trim be converted into a confirmed order.

 

[WildRide47]

I have two questions:

1. Will any of the trims of the Lucid Air come with a heated steering wheel for those cold winter mornings.

2. Same question concerning power folding exterior mirrors, so that your outside mirror does not get scraped by someone parking too close to you.

Answers received from SA below.

• We can confirm that at least the Dream Edition with have the heated steering wheel, more information will come soon whether it is included on the other trims as well.
• The Lucid Air will also have power folding side view mirrors, the command can be accessed from the center pilot panel.

 

[Adnillien]

Over the weekend, Inside EVs posted the best pictures that I have seen so far of the Lucid battery module.

I cannot tell for sure but this looks like a very interesting wiring scheme with both series and parallel strings in each column of 30 cells. This may simplify the main battery buss by putting it in the center of the car.

One other interesting point is that the end flanges on the the injection molded module above do not match the end flange shown in the overall battery pack image. Is one of them an earlier version?

It was not in this article, but I have heard that Lucid is using an Aluminum buss within the battery pack to reduce resistance. This is interesting since Al has 58% higher resistance than Cu. Hence, an AL wire will need to be 58% larger than Cu to have the same total resistance. That said, Al is also 70% lighter weight than Cu. You can have a larger conductor with a lower weight when using Al rather than Cu. If Lucid is using Al battery connections, it is for weight reduction more than resistance reduction.

 

[SDHacker]

https://spectrum.ieee.org/lucid-air-500-miles-ev
If you don't want to read the entire article, this is the pertinent text for this discussion:
"A Lucid innovation connects cells with slender aluminum ribbon instead of wire, saving a claimed 80 horsepower that would otherwise be wasted in electrical resistance. Those battery cells are fixed with adhesive and cured for 26 minutes. A metal cooling plate, the new standard in EV packs—which Tesla will soon adopt, eliminating a space-wasting thermal circuit—dissipates heat from terminal ends."

You can see the ribbon in the right photo of the tray. According to a manufacturer of AL wire and ribbon along with Cu and gold:
" Coining also offers Al ribbon which is typically utilized in microwave and high power applications. Choice between wire or ribbon is determined by several factors. Ribbon offers better electrical characteristics, improved heat dissipation, fewer bonds, improved throughput and increased reliability over wire. "

Haven't seen any info on the buss or busbar

 

[Adnillien]

In case there is any speculation about the number of battery cells in the GT being different than the Dream, this is from Lucid filing with the EPA.

It is hard to read but there is useful information in the filing. Here is a link to it: https://iaspub.epa.gov/otaqpub/display_file.jsp?docid=53965&flag=1

 

[dawktah LucidGT]

I'm digging what's on page 12 section 08.08.02

 

[hmp10]

I'm still wondering if the Samsung cell chemistry allows Lucid to reduce the buffers in the Dream battery pack, thereby making more of the pack user accessible.

 

[hmp10]

I'm digging what's on page 12 section 08.08.02

That is only available at home when using the Lucid wall connector which is not yet available. With the portable cable that will come with the car the charging rate is 9.6 kW.

 

[hmp10]

I found this very interesting -- the power outputs of the Dream P, Dream R, and GT motors:

I'm thinking back to what Zak Edson said late last year about the Dream Edition using a rear motor with special metallurgy that he said only bumped the horsepower up by 15 hp but yielded a greater increase in torque.

This chart shows only minor power differences in the rear motors across the three versions (with the rear motor of the Dream P actually putting out less power than the Dream R's rear motor) . . . but with a huge bump up in power for the Dream P's front motor.

I wonder what that's all about? Is there any "special metallurgy" still bumping about but now maybe playing a role in the front motor?

 

[Adnillien]

With the small differences in rear power it is hard to see why a special metallurgy to allow higher torque would be needed.

 

[dawktah LucidGT]

That is only available at home when using the Lucid wall connector which is not yet available. With the portable cable that will come with the car the charging rate is 9.6 kW.

Its rated at 19.2kW Which means until battery has discharge to the protection point you can run to the house equivalent to a $6,000 air cooled or $11,000 liquid cooled generator.

 

[SDHacker]

Engine power is expressed two ways, HP (kW) and torque (N-M or lbs-ft). You're questioning what's different about the torque between DE and GT. Here's the torque rating for the 3 trims:
Both DE: 1,390 N-M or 1,025 lb-ft
GT: 1,200 N-M or 885 lb-ft

So there is a significant difference in torque. According to the motortrend article, this is peak torque accessible only in sprint mode. Jonny listed the torque for each driving mode for the R and P.

 

[hmp10]

With the small differences in rear power it is hard to see why a special metallurgy to allow higher torque would be needed.

There have been so many engineering changes in the power- and drivetrains over the past year that I wonder if anything I heard a year ago has any bearing today. Rawlinson did say in one interview that he liked to talk only about horsepower, as torque was not really a relevant metric for EVs -- a point I did not understand.

Another thing I don't understand is why the Dream P would have lower power output at the rear than the Dream R, since rearward weight transfer under acceleration would seem to call for more power from the rear to get faster acceleration numbers.

And are the front motors the same across the three models? Does it make sense that the same motor that produces 370 kW in one version would be set up to produce only 178 kW in another?

 

[dawktah LucidGT]

And are the front motors the same across the three models? Does it make sense that the same motor that produces 370 kW in one version would be set up to produce only 178 kW in another?

Let's hope not, this would indicate the hobbling I was afraid of.