🔋 The Extended Battery Decision (Poll: Which battery option suits you best?)

[RetiredOnPaper]

Many years ago when I did the deep-dive into EVs and continuing to today, weight affects range far less than wind resistance (drag). It is my wish that there was some other way to measure range. A battery less than one year old is not the same as one that is 2 to 5 years old or one that is 7+ years. Now some of this is based on my Tesla and me thinks that the updates monkey with the range estimates. (Nearly every weekend I drive the same 98 mile route, summer and winter. Somehow regardless of what the range is for 100% charge, the trip "costs" me the same amount of range at a given temperature.) I have learned, plug in, charge up, don't worry, be happy!

 

[AZFox]

Now some of this is based on my Tesla and me thinks that the updates monkey with the range estimates.

I wouldn't be surprised if some range was held in reserve and the indicated range is gradually adjusted with firmware updates.

Made-up Example:
New: 100% indicated is 95% actual
Later: 100% indicated is 97% actual (after actual has diminished)

Keeping maximum range artificially more consistent would help reduce disappointment about losing range over time and provide a more satisfying ownership experience.

 

[Daemoch]

I remember reading from multiple sources that Tesla holds back some cells for thermal and wear leveling purposes. IIRC, the overdive speed boost or whatever they call it allows you to access all available cells for a very short moment - something like 10 seconds.

 

[AZFox]

I remember reading from multiple sources that Tesla holds back some cells for thermal and wear leveling purposes.

Interesting. That's slightly different that what I was thinking.

Similarly, hard drives (and other storage media) have "reserved sectors" that can get mapped in as a replacement if a sector fails.

 

[Daemoch]

Similarly, hard drives (and other storage media) have "reserved sectors" that can get mapped in as a replacement if a sector fails.

Yup, 100%. Almost all the SSD type technology has something to that degree, usually even more so. Thats the industry I spend most my time working in.

 

[atreis]

I remember reading from multiple sources that Tesla holds back some cells for thermal and wear leveling purposes.

Most manufacturers do. My car (Nissan Ariya) has a 90 kWh pack, with 87 kWh usable. Hyundai/Kia are similar. Most don't let you access that extra capacity though.

 

[AZFox]

I remember during a hurricane Tesla flashed more capacity to cars in the area.

Found it. Hurricane Irma in 2017. They added 30-40 more miles to the range with the update.

 

[KevinRS]

In part that "reserve capacity" is so they can keep giving you the same range years down the road. Cell phone manufacturers are starting to do similar,

 

[FunkyFinch57]

I remember during a hurricane Tesla flashed more capacity to cars in the area.

Found it. Hurricane Irma in 2017. They added 30-40 more miles to the range with the update.

i get why they did it, and why they don’t always have that extra capacity available… but that seriously strikes a bad note with me. If the vehicle I own is factory capable of something, it would seem reasonable to permit the user to access it without the permission of its over-the-air update overlord.

 

[sodamo]

i get why they did it, and why they don’t always have that extra capacity available… but that seriously strikes a bad note with me. If the vehicle I own is factory capable of something, it would seem reasonable to permit the user to access it without the permission of its over-the-air update overlord.

Is that much different from current ICE vehicles that read Low Fuel - Empty when in reality there may be a couple gallons left?

 

[SichuanHot]

i get why they did it, and why they don’t always have that extra capacity available… but that seriously strikes a bad note with me. If the vehicle I own is factory capable of something, it would seem reasonable to permit the user to access it without the permission of its over-the-air update overlord.

The manufacturers probably do that because they don't want to be held liable for irresponsible owners driving the battery voltage down to under 2.5v per cell potentially leading to premature battery failure. The OTA changing what your car can do on the fly is concerning though. Slate's selling point of no cellular modems in the car is a plus in that regard.

Is that much different from current ICE vehicles that read Low Fuel - Empty when in reality there may be a couple gallons left?

I think what's more analogous to ICE cars is ECU purposefully being detuned or turbo boost being limited. In both instances you're not getting the full hypothetical potential of the car.

 

[cadblu]

i get why they did it, and why they don’t always have that extra capacity available… but that seriously strikes a bad note with me. If the vehicle I own is factory capable of something, it would seem reasonable to permit the user to access it without the permission of its over-the-air update overlord.

To your point, Tesla at one time offered an OTA performance boost on certain models that users could access… but you needed to pay for it.