Battery Design and Info

[Leo Shapiro]

Curious how long we can expect the battery to last if we live somewhere extremely hot half the year like in the Phoenix area. Interior car temps can get to around 160+ if you leave your car unshaded.

[Joshua Rosen]

The car will have active battery temperature management. Assuming they do the right thing the thermal management will run when the battery temperature reaches it’s upper and lower bounds.

[Leo Shapiro]

Should I expect the battery to drain managing temperature?

[Dennis Swaney]

No, because it will be charging from the solar cells.

[James G]

According to CA, the 66kWh & 99kWh packs, will utilize “fatter and taller” cells.

Does that mean, one of the Aptera suppliers (and recently tapped by BMW, according to an Electrek article link below) EVE Energy would supply the 4680s “Tesla” cells for these bigger 2nd & 4rth production pack releases?

https://electrek.co/2022/09/09/bmw-confirms-it-will-adopt-teslas-4680-cells-pledging-six-ev-battery-factories/

[kerbe2705]

@James Gatan To add to what @Curtis Cibinel mentioned, there’s a 2665 cell currently in manufacture: Where 2170 cells have capacities between 4000 and 5000 mAh, 2665 cells have capacities up to 10,000 mAh. The only fly in this suppositional ointment is that Chris said “fatter and taller”: 2665 cells are taller, but more slender than 2170 cells…

[Thomas Edmonds]

Tesla is using Lithium Iron Phosphate. Are we, and / or should we?

[Curtis Cibinel]

Aptera 45kwh is designed using NMC 811 2170 cells from EVE; LFP was not adequate for anything past the 250 mile Aptera in 2019 but it has evolved. The larger Aptera packs (600/1000) have been said to use larger form factors which could be 4680 or 2665. LFP could definitely be a viable option for Aptera but was not when development started. Modern LFP and LFMP chemistries are pushing above 200 wh/kg which is definitely viable for ranges up to 600 miles. Aptera currently needs to focus on getting the current design refined and into production. I suspect at minimum the 250 and 400 will switch within the first 1-2 years of production. LFP chemistries could potentially save $1000-3000 per vehicle which is critical profit margin. Assuming 2c discharge LFP could end up slightly power limiting the 400 mile vehicle so 0-60 times could be hurt a little (and the 250 would be substantially power limited with only 46KW / 150KW peak for AWD).

On the charging front LFP and NMC cells typically have rated max C rates for charging of 2C. Tesla charges at a peak of 4.5C with DCFC with substantially more cooling and packs approximately equal to the 600 mile Aptera. It is possible if the Aptera cooling can keep up larger packs MIGHT be able to charge faster than 50KW (assuming all components could handle it). LFP might impact charge rates.

[John Voules]

Here’s some common Evs and their winter loss stats.

D82B418E-2D01-4196-B518-8A19B5BA6882.png 1 MB Image File — Click to view

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[David Marlow]

There are a lot of things about winter driving that will reduce range in any vehicle, however in EV’s the greatest is how you use the electric cabin heater. My experirnce in my Volt tells me this.

[James Elliott]

Tesla’s early design resulted in battery damage (and fires) from belly pan damage when encountering road hazards. The Delta design has an aluminum belly pan. Heat transfer is enhanced, but road hazards such as truck tire treads may cause severe damage to aluminum. What is Aptera’s answer to this problem?

[Bob Kirchner]

My understanding is that the alumin(i)um belly pan will not be in contact with the battery pack. There is some crush space between them.

[John Hermann]

If it wasn’t the 100kwh design, then I’m starting to question whether the promise of a 1,000-mile range capability is anything but vaporware.

[Bob Kirchner]

It will be 42 kWh/400 miles for the launch edition, I think.

The 1000 mile version may very well require advancements in battery energy density beyond what is currently available, which is probably why it will be the last to be released.

It almost certainly isn’t possible with the cells they are using for the Launch Edition, but advancements occur daily.

[John Hermann]

That’s kind of what I was looking at with the render video. It’s simply a matter of energy density. If the form factor they used for the render is representative of the 42kwh pack then I’m starting to question whether there is physical space available for a pack roughly 2.5x the size.

[David Marlow]

I know that different batteries have different rates of charging efficency.

Too slow or too fast are not as good as the sweet spot in the middle.

Evendently Aptera has looked at that and with all things concidered, found that the level 2 charging will be best, as their main direction is towards efficency.

[John Malcom]

I think Aptera stopped working on maturing the development of DCFC for cost, weight, schedule and Perhaps because of the adoption of the Tesla plug, not because Level 2 is a sweet spot. As indicated by the response of the market, DCFC is a essential feature of EV’s for road trips regardless of the effect on battery health. Level 2 is harmful for battery health if constantly charge from a very low state to full charge.

[kerbe2705]

@David Marlow IMHO this isn’t about “battery efficiency”, it’s about the fact that DCFC makes batteries HOT and, when it’s not moving, Aptera has no way of shedding excess heat. In the past they’ve mentioned the need to develop a system to cool the pack while charging and I’m guessing they haven’t yet come up with one that works sufficiently.

Remember, they’re still hoping that “belly cooling” will work: They haven’t yet tried it on an actual vehicle…

[David Marlow]

Heat represents ineficency, however there is a lot that goes into measuring efficency, getting energy into and out of a battery can have different efficency rates. Also the efficency of the charging and discharging circuits also play a part.

[Richard Palmisano]

This is not going to sit well with some…

Ok, the launch event had the glaring elephant in the room: No DCFC. That was a complete swing and a miss. Fortunately, they listen. The Forum, the community, the investors all literally had bile in their mouths at that news and voiced their opinions, apparently very loudly, that this was unacceptable. How could they not have seen this?

So it begs the question: Is Apteras focus on Battery and Thermal Management Planning, the MOST IMPORTANT ASPECT of an EV, not on par with other manufacturers?

It makes sense for a 40kwh(ish) pack to be able to recover half charge in less than an hour, IMHO. So the DCFC system should ALWAYS have been in the crosshairs for 50kw of DCFC, so that when you go from say 20%-80% you can achieve this in about 45 minutes. I, as well as most EV enthusiasts, find this acceptable. It’s still not world class, but highly acceptable to get 200+ miles of range in one fast charging session.

Is Aptera’s Thermal Management an issue? Can they get the cooling they claim from the belly of the vehicle? It always seemed to be a complex idea, having cooling in the body. Seems like a recipe for disaster honestly.

If they had the system already, 40-60kw DC charging, but decided against it for complexity reasons, how then can they add it without complexity? Without better thermal management? There seems to be some explaining to do and honestly, I don’t think they can…at least yet. They need to get into production. They were willing to produce the vehicle without DCFC and tell you, “most won’t likely need it”, which they found out quickly that MOST DO! This is a little disturbing.

I would like to know how they could prepare a launch without DCFC, and then turn 180 a few days later? THIS IS YOUR PRODUCT LAUNCH! This is where you say, here it is! Oh wait, you wanted what??? DC charging??? We didn’t think of that.

Scary bad…just not good.

• This reply was modified 6 days, 20 hours ago by  Richard Palmisano.
• This reply was modified 4 days, 12 hours ago by  Gabriel Kemeny.

[Joel Smith]

I wish they would have come right out and said in the back-peddle video that they already have the battery thermal management to handle DCFC incorporated since that was the dominant assumed deficiency that folks were attributing the lack of DCFC to. Instead they divert us to thinking of the paused PDU development without mentioning thermal management. I’d like to think of this as engineers ignoring irrelevancies and getting to the root of the issue. Still feels a bit like political re-direction to avoid an uncomfortable answer to the real question.

Still it is obvious they got the message and I guess we will see how it all shakes out.

• This reply was modified 6 days, 18 hours ago by  Joel Smith.
• This reply was modified 4 days, 12 hours ago by  Gabriel Kemeny.

[Hee-Choon Lee]

I ageee with Richard. While it is commendable for Aptera to do a quick turn on its bombshell, the question raised re the battery management desperately calls out for a clean explanation.

[Richard Palmisano]

Yes sir. My main question would be:

Since you designed a 40-60kw rate charger, had the trim and positions for it, and had test runs on the bench, why not go forward? Are they so cash poor right now that they can’t verify and install the most basic necessity for an EV? Yeah, I get it, it’s a “Solar Vehicle”. No. It’s an EV with a solar add on…

[David Marlow]

While 98% of the time I won’t need fast charging, I do want to have it available for long trips. I realise that using fast charging reduces the life of the batteries.

Any heating of the batteries reduces their life, especialy at or near full charge and fast charging creates much more heat in the cells than level 2 charging.

[James Lee]

I’m wondering about the constant solar charging and the degradation of the batteries, constantly topping off a lithium battery is bad for it no ?

I was told and have read that if you drain your phone down for instance to 75% and then fully charge it , that the batteries now think 75% is zero anymore only hold a charge down to 75% and then require recharging every time.

https://news.ucr.edu/articles/2020/03/11/fast-charging-damages-electric-car-batteries

[Barry Jewett]

Is it possible that there was an underlying issue that needed this sort of “Webinar” presentation, to make a clear point? Something just feels off. We all have responded for them to clarify a point.

For what?

For who?…

• This reply was modified 5 days ago by  Barry Jewett.
• This reply was modified 5 days ago by  Gabriel Kemeny.

[Gabriel Kemeny]

At about 2:20 in this video, Chris Anthony provides answers to some of the issues raised by Richard:

Aptera CEO Chris Anthony Talks Launch Edition with DC Fast Charging – YouTube