AC Preconditioning Impact on Range

[Adnillien]

I frequently charge at work and since it was 95 outside yesterday, I tried the pre-cool function to see how quickly it cooled and how it impacted my charge rate. Here are some notes on interior temperature and power draw:

	Charge rate mi/hr	Power In	Interior Temperature
Prior to starting AC	21	6 kW	134
Just after starting AC	0.0	6 kW	134
5 minutes in	0.0	6 kW	112
10 minutes in	0.0	6 kw	94
15 minutes in	0.0	6 kW	91
20 minutes in	0.0	6 kW	89

I used the preconditioning once before an noticed after 10 minutes that the charge rate went back to about 10 mi/hr so I was expecting to see this but gave up after 20 minutes. It is interesting how the cooling rate is great for the 1st 10 minutes then really slows down. Below are a few screen shots from the app, note the bug app showing the option to turn on AC rather than off.

It appears that the AC on full consumes about 6 kW since the battery was no longer charging and in fact lost 1% SOC. I assume that would go down by at least half when driving and the interior was at a stable temperature. Taking my GT with 21"wheels, the EPA rating is 4.19 mi/kWhr. Assume that I drive for one hour at 70 mi/hr and that the GT would get 96% of EPA that Tom Moloughney got with the DE range edition at 70 mi/hr. Here is the resulting efficiency.

• No AC - 4.02 mi/kWhr
• AC using 3kW - 3.43 mi/kWhr
• AC using 6kW - 2.99 mi/kWhr

It may not be all that surprising that Lucid owners in hot climates are seeing efficiencies in the low 3's.

 

[hydbob]

Wtf 134...

 

[Adnillien]

Wtf 134...

Welcome to Phoenix, internal temp over 150 in June.

 

[hydbob]

Welcome to Phoenix, internal temp over 150 in June.

Yea I think that big drop in cooling rate is mainly just a factor of cycling the hot air out and getting the cooling going. I suspect it would be the same for almost any AC system

 

[Boomer AZ]

Welcome to Phoenix, internal temp over 150 in June.

During the summer some have oven mitts in their cars so that they can hold the steering wheel. Bare metal on a seat belt can burn the skin. I’ve seen people in parkas walking between building. It hold the cool in and the heat out. And am constantly amazed by those who won’t use their car’s AC and drive around with the windows down. It’s a dry heat only applies in June when the humidity is less than 10%.

 

[Adnillien]

Yea I think that big drop in cooling rate is mainly just a factor of cycling the hot air out and getting the cooling going. I suspect it would be the same for almost any AC system

I agree, there is noting unusual about this or different than an ICE car. Lucid is the first car that i have owned that gives any information about how much power is taken by AC.

 

[Not Sam]

Something here doesn't make sense to me. 6 kW is a lot of power for an A/C unit. For comparison, this window A/C unit takes about 1.5 kW (one quarter the power) and is designed to cool a 1000-sqft room. I suspect that the battery really is getting charged, and the display of "0.0 mi/hr" is wrong (or just being recalculated).

Edit: Oh, I just noticed the part of the original post where the SOC went down. hmm.

 

[Not Sam]

Something here doesn't make sense to me. 6 kW is a lot of power for an A/C unit. For comparison, this window A/C unit takes about 1.5 kW (one quarter the power) and is designed to cool a 1000-sqft room. I suspect that the battery really is getting charged, and the display of "0.0 mi/hr" is wrong (or just being recalculated).

Or maybe if you're pulling out of the main battery (as we presumably have to with the a/c), the L2 charging has to be stopped temporarily? This wouldn't explain the 10 mi/hr @Adnillien saw in a prior session, but maybe in that case the a/c was cycling on and off and thus the average charge rate was lower but nonzero? Still a bit odd though since I imagine sitting in the car with the a/c on and charging with L2 is not that infrequent.

 

[Steveinarizona]

When I play golf in the summer I take out my phone and precondition the interior after the 17th hole on my BMW 530e. Works great doing that. By the time I finish and get to my car, it is always comfortable despite temperatures north of 110.

But that is another reason why a large range is important...at least to me.

 

[mnewber1]

Holy moly 134. I don't think we could hit that interior temp here if I tried, thanks for this information nonetheless.

 

[Adnillien]

Or maybe if you're pulling out of the main battery (as we presumably have to with the a/c), the L2 charging has to be stopped temporarily? This wouldn't explain the 10 mi/hr @Adnillien saw in a prior session, but maybe in that case the a/c was cycling on and off and thus the average charge rate was lower but nonzero? Still a bit odd though since I imagine sitting in the car with the a/c on and charging with L2 is not that infrequent.

This was an interesting thought so I asked my Scottsdale Service manager about Level 2 charging and running AC at the same time. His comment is that the AC can run during Level 2 charging. He also pointed out that thermal management is active for the battery during Level 2 charging so it makes sense that the AC could also operate during charging. When you set the interior temperature though the App, AC takes priority over charging and the charging rate can go all of the way to zero if needed. The 6 kW draw seemed possible to him.

 

[Pete44]

This was an interesting thought so I asked my Scottsdale Service manager about Level 2 charging and running AC at the same time. His comment is that the AC can run during Level 2 charging. He also pointed out that thermal management is active for the battery during Level 2 charging so it makes sense that the AC could also operate during charging. When you set the interior temperature though the App, AC takes priority over charging and the charging rate can go all of the way to zero if needed. The 6 kW draw seemed possible to him.

So now you need to run the real test by activating the A/C while sitting in the car while charging and seeing the tradeoff between charging and melting your skin. I'm sure the 134 degrees won't bother someone from Arizona.

 

[digiboxer]

This isn't so much of an indictment of Lucid as it is the whole EV industry, circa 2022.

The general paradigm is suspect, based on current, best-tech practices---eg shlepping around thousands of pounds of batteries just to drive over and buy half a pound of butter.

One reality of these real-world-downer stories is that the EPA's mpg-equivalent stats are totally bogus (OK, I know their ICE mpg stats are inflated too), meaning less efficiency, more electricity generated by carbon fuels, etc.etc.

As I've said, I'll stay in the queue knowing my T delivery is > 6 months out...feeling a bit guilty for my brethren here who have ventured forth and wire transferred)

 

[Sam6062]

I frequently charge at work and since it was 95 outside yesterday, I tried the pre-cool function to see how quickly it cooled and how it impacted my charge rate. Here are some notes on interior temperature and power draw:

	Charge rate mi/hr	Power In	Interior Temperature
Prior to starting AC	21	6 kW	134
Just after starting AC	0.0	6 kW	134
5 minutes in	0.0	6 kW	112
10 minutes in	0.0	6 kw	94
15 minutes in	0.0	6 kW	91
20 minutes in	0.0	6 kW	89

I used the preconditioning once before an noticed after 10 minutes that the charge rate went back to about 10 mi/hr so I was expecting to see this but gave up after 20 minutes. It is interesting how the cooling rate is great for the 1st 10 minutes then really slows down. Below are a few screen shots from the app, note the bug app showing the option to turn on AC rather than off.

It appears that the AC on full consumes about 6 kW since the battery was no longer charging and in fact lost 1% SOC. I assume that would go down by at least half when driving and the interior was at a stable temperature. Taking my GT with 21"wheels, the EPA rating is 4.19 mi/kWhr. Assume that I drive for one hour at 70 mi/hr and that the GT would get 96% of EPA that Tom Moloughney got with the DE range edition at 70 mi/hr. Here is the resulting efficiency.

• No AC - 4.02 mi/kWhr
• AC using 3kW - 3.43 mi/kWhr
• AC using 6kW - 2.99 mi/kWhr

It may not be all that surprising that Lucid owners in hot climates are seeing efficiencies in the low 3's.


View attachment 1796View attachment 1797

You are absolutely correct. In Texas I use AC at 60 degrees and Fan speed 9 or 10 and have never achieved more than a 3.3 Average over 1675 Miles. AC is a huge weak link here and truly sucks in Hot climates but some people would not acknowledge that.