Battery Losing Range at Low SOC

[johnse]

I know that with Teslas the BMS will do cell balancing at the top of the charging process... between about 92% and 100% IIRC. So it's often suggested to charge to 100% occasionally and immediately drive it so it doesn't sit at the high SOC. Subsequently running it down to single-digit SOC helps the BMS to calibrate the present capacity.

Is that also true for Lucid?

 

[Bobby]

My 2017 chevy Bolt does a better job

I don't know why I find this post so irritating, but I do.

 

[Lucken]

I don't know why I find this post so irritating, but I do.

Because you weren’t aware you could have had a much better car for much less money!

 

[WhistleKing30]

I know that with Teslas the BMS will do cell balancing at the top of the charging process... between about 92% and 100% IIRC. So it's often suggested to charge to 100% occasionally and immediately drive it so it doesn't sit at the high SOC. Subsequently running it down to single-digit SOC helps the BMS to calibrate the present capacity.

Is that also true for Lucid?

True for all lithium-based cell chemistries, which includes Lucid. But also good to remember that this does little for the health of the battery itself - rather the opposite if anything. I've encountered people who almost religiously tried "calibrating their battery" by ramming it up to 100% and going as deep as 1-2% as often and once per week. Totally unnecessary, and likely to increase degradation.

 

[Samo23]

I don't know why I find this post so irritating, but I do.

Stay on topic or your posts are subject to being removed

 

[borski]

Stay on topic or your posts are subject to being removed

Your 2017 Chevy Bolt was not on topic. What’s that saying about throwing stones in glass houses?

 

[Samo23]

Your 2017 Chevy Bolt was not on topic. What’s that saying about throwing stones in glass houses?

That's fair

 

[Bonanzajohn]

is the cooling while out ot the car part of the equation

 

[Worldwide Beagle]

Such different mindsets here.

Remaining miles has always been a snapshot guesstimate. Audi's for decades still give one guesstimate when hot, at 9pm after a drive when below 1/8 tank, and a very different one when cool the next morning. Normal.

Drove with someone in a Tesla last week for 100 mile trip. I asked if we could stop for coffee. Said we couldn't. Not enough juice to stop and then to get home. He purposely left his house in the AM with the level of charge at just enough juice so he would arrive back home with a few percent left. Has two Tesla chargers in his garage. Didn't see the need to top up overnight and start out with a full battery "since (he) would have a few percent to spare.".

 

[Worldwide Beagle]

is the cooling while out ot the car part of the equation

I have found, not really. Pleasantly surprised how little juice Dog mode uses.

 

[Pragmatic]

Keeping the car hot or cool does not use a lot of energy. Cooling a hot car or heating a cold one does use alot of energy.

 

[LucidJK]

I am a bit surprised at some of the seeming skepticism directed at the OP of this post, though maybe I'm not skeptical because the same thing has happened to me on a couple of occasions. Similar to the situation with the OP. If the car is at a relatively high state of charge, vampire drain is pretty minimal. If it's around or below 20%, it vampire drains pretty fast.

In my case, I parked my car on a Wednesday, knowing the next time I would need the car would not be until Sunday. I was planning to meet up with my friend for lunch and then would charge my car afterwards (for those wondering, I don't have home charging because I live in a condo. I'm allowed to install one, but it's a bit of a pain). I knew I would be driving a total of about 30 miles, so when I left the car on Wednesday with a little over 90 miles, I figured this would be plenty. Unfortunately, by the time I got in the car on Sunday, I was below 50 miles of range left, which basically torpedoed my initial plan. In addition, my Trip odometer, which had efficiency in the 3.5 kwh/mi range when I parked it, had gone down to below 2 kwh/mi. This to me is much more consistent with "battery losing charge at low SOC" than "car bad at guessing mileage". I'm guessing, based on the other posts in this thread, that I might have a bad cell.

Incidentally, something similar also happened to my once in my previous car (Model 3), though that was not at low SOC, it just randomly started vampire draining like crazy. However, my 12V battery also went bad at around that time, so I think that one might have been related to that, rather than a bad cell, being as replacement of the 12V and rebooting of the car seemed to address it.

Anyway, I'm guessing maybe some of the skepticism is related to the fact that if you home charge, you'll basically never see this problem even if you have it. When you can't home charge you are generally much more keenly aware of vampire drain than if you're charging your car on a daily basis.

 

[Samo23]

I am a bit surprised at some of the seeming skepticism directed at the OP of this post, though maybe I'm not skeptical because the same thing has happened to me on a couple of occasions. Similar to the situation with the OP. If the car is at a relatively high state of charge, vampire drain is pretty minimal. If it's around or below 20%, it vampire drains pretty fast.

In my case, I parked my car on a Wednesday, knowing the next time I would need the car would not be until Sunday. I was planning to meet up with my friend for lunch and then would charge my car afterwards (for those wondering, I don't have home charging because I live in a condo. I'm allowed to install one, but it's a bit of a pain). I knew I would be driving a total of about 30 miles, so when I left the car on Wednesday with a little over 90 miles, I figured this would be plenty. Unfortunately, by the time I got in the car on Sunday, I was below 50 miles of range left, which basically torpedoed my initial plan. In addition, my Trip odometer, which had efficiency in the 3.5 kwh/mi range when I parked it, had gone down to below 2 kwh/mi. This to me is much more consistent with "battery losing charge at low SOC" than "car bad at guessing mileage". I'm guessing, based on the other posts in this thread, that I might have a bad cell.

Incidentally, something similar also happened to my once in my previous car (Model 3), though that was not at low SOC, it just randomly started vampire draining like crazy. However, my 12V battery also went bad at around that time, so I think that one might have been related to that, rather than a bad cell, being as replacement of the 12V and rebooting of the car seemed to address it.

Anyway, I'm guessing maybe some of the skepticism is related to the fact that if you home charge, you'll basically never see this problem even if you have it. When you can't home charge you are generally much more keenly aware of vampire drain than if you're charging your car on a daily basis.

No dude its for sure just that you've miscalculated the calculation of having a home charger (or a home at all) or 3 other cars in your garage

Would really solve your problems. Don't let the car get below 20%! Wait.....thats 100
miles of range?

Don't trust anything below 100 miles in your cars battery, that's totally normal for a $160,000 car!

No in all seriousness go have them do a battery drain test and check your cell voltages at the SC. Don't listen to this thread of nonsense

 

[L-Dude]

Personally I don't think the range estimates are very accurate at low SOCs. Range estimates are real time, made at a specific point in time. If you end a long drive with the car completely warmed up and the cabin at a steady temp, you are probably going to get a different estimate than when the car has been sitting, the batteries have cooled down, the tires are cold, and climate control needs to get everything up to temp. I think this is just the nature of how the car makes these estimates.

I had an experience the other evening where I had 69 miles of estimated range remaining for a 50 mile trip. There was only one charger along my route, and it was 30 miles away. My experience from my Audi's GOM told me I shouldn't rely on the estimate. I also didn't have any experience with the Air's range estimating capabilities, so I thought it was best to top off for a couple minutes to be on the safe side (FWIW the car also warned me that I didn't have enough range). I topped up the car to 104 miles of range (at a 300kW charge rate ), and ended up with 55 miles of range remaining when I got home. I was impressed with the range estimates from the car.

But who knows what the range estimate would have been if the car had sat overnight before setting out.

 

[borski]

Personally I don't think the range estimates are very accurate at low SOCs. Range estimates are real time, made at a specific point in time. If you end a long drive with the car completely warmed up and the cabin at a steady temp, you are probably going to get a different estimate than when the car has been sitting, the batteries have cooled down, the tires are cold, and climate control needs to get everything up to temp. I think this is just the nature of how the car makes these estimates.

This is the correct answer.

 

[LucidJK]

This is the correct answer.

Yeah, I don't think it is. TRIP ESTIMATES are real time, with all the caveats that L-Dude mentioned. Range estimates appear to just be the remaining kWh remaining in the battery times 5 (at least for the Pure, which has a rated efficiency of 5 miles/kWh). That's why in the Tesla (and the Lucid) you're better off completely ignoring the Range Estimate, unless your lifetime efficiency is remotely close to 5, which it certainly isn't for me. Trip estimates in the Model 3 were always quite accurate, because they're taking in to account all the factors that L-Dude mentioned (including weather, elevation changes, etc).

I don't think anyone's expecting the Range Estimate to be accurate, because it's inaccurate regardless of SOC (I assure you, I'm never getting anywhere close to 420 miles on a full charge). What should never happen is for my car to lose significant mileage (or kWh if you prefer) while it is sitting there doing nothing. In my 7 years of owning electric vehicles this has only happened once in my Tesla, but it happens all the time in my Lucid.

For example, I checked my car via the app on last Thursday. I had 157 miles in remaining range. The car had not been driven since Sunday. I checked the car on Saturday night and I had 140 miles of range. Is 157 high enough for you? Or is that still low SOC? Even if you think this is an "estimates" problem, if the car (which is in an underground parking garage) produces a significantly different range between Thursday, when it had been sitting around undriven for 4 days, and Saturday, when it had been sitting around undriven for 6 days, then your estimates are terrible and require immediate improvement.