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Whether it's the first or last 20% of the battery is a software problem: People adjust their driving habits to avoid running out of charge, in the same way that people adjust their driving habits to not run out of gas. A car losing power when it claims to still have 20% left is a big problem, because it's failing to present you with the information with which to base your plan. If the readout on my car simply said that it had 240 miles of range on a full charge instead of 300, there's a good chance I wouldn't even notice.

On the exceptionally rare instance that I'm driving more than 200 miles in a day, I appreciate the half an hour to stretch my legs and grab a snack while my car's on a fast charger.

it's only software until the hardware becomes the boundary condition.

You're right for many drivers with dense charger coverage it's a nuisance.

But there are drivers who take trips with sparse charger coverage , where the 20% loss means insecure or impossible trips.

You really need to be in the middle of nowhere for a 200 mile range to be a problem. I've made quite a few trips in my Bolt where I worried there wouldn't be coverage (rural Indiana was my biggest concern), but it consistently turned out to be unfounded. In rural areas chargers certainly thin out, but you can safely drive the interstates and the vast majority of state highway with less than 100 miles between chargers.

The fact is you felt insecure because there was a risk. And with growing degradation means more of a buffer is needed. A 300 mi range vehicle is 192mi due to the buffer, and even that dwindles.

Only half of the non-Tesla EV chargers work, so your 200 mile charger now takes 6 hours to do the next 200 miles.

Even super chargers only function well over the bottom 50% of the battery . So the usable window is shrinking and shrinking.

All of these practical insecurities will need to be fixed before EVs expand beyond just a niche product.

You can dismiss them as silly or user error, but you won't sell any more vehicles that way.

Can you please share some (non-byzantine) trips that you can't make with only 80% battery capacity? Let's assume 240mi (80% of 300), since that seems to be about the average EV range nowadays.

Yeah, I had a model S for about 4 years and struggled with the bottom 20%. Everything becomes a stressful game of can I make it if the wind is too high. Part of this issue will be solved with more charging stations but the other part is degradation as you said.

I can relate. I've gotten pretty confident by watching the *consumption tab -- but i don't think most drivers should have to .

I think the ones who dismiss this issue drive regular routes with the EV and don't push the boundaries . Then there are the rest of us who actually try to test the limits where you encounter a good deal of unsettling unpredictability .

I've pulled supercharger data and found discrepancies between the before and after kwh delivered -- explaining some discrepancies in the charging and forecasts. I don't think anyone else has gone into that level of detail.

If the top of your charge level is the "last 20%", then you can have two or three or four or more "last 20%"s by buying a bigger battery.

I'd say the opposite, that you're losing the first 20% as your battery degrades, which is the least important part. And if you need a specific range for some trip, again just size your battery appropriately. Make sure 80% or 70% of the brand new range is enough for that trip.

Depending on the car brand you can drive several dozen kilometers even after hitting 0%.

Fully emptying an electric car is a boring exercise in stupidity. Unless you are going out of your way to do it, you will never run into a situation where you need to get your car towed.

That’s not true. I have documented a forecasting calibration issue specific to certain supercharging scenarios where the forecast drops 10% upon departure . The driver can follow the plan and still go below 0

"Electric owners under-value the last 20% of their battery. That is the most important 20%"

It's not exactly like an ICE. An ICE (in Europe) will put up a warning light at "I have roughly 50 miles left" you put your max speed at 50mph and find a garage. Job done.

I've owned quite a few of them over 30 years. I currently have a MG4 (Saic) Long Range and an elderly Renault Clio. The EV has a demonstrable range of at least 300 miles. UK temperatures. The Clio can do around 600 miles on a full tank.

I treat my EV in a similar way to my ICE. When it says it has 50 miles left, I look for petrol or sparks. That works here, now in the UK. It will work in quite a lot of Europe, some of the US, and will be laughable in most of Australia and Canada, most of Africa, ... anyway you get the idea.

They - ICE and EV are simply different. You have to learn to work with how they operate.

Oh and I pay £1.28 per litre and 7p per KWh (for overnight car charging). The petrol price is low at the moment for here (it hit £2+ when Russia went mental).

Quite loose numbers:

600 mi using 50 litres at £1.30 per litre is £65. 300 mi using 70 kWh at £0.07 per kWh is £4.90 say £5.

So, less than 20% cost in fuel (£65 vs £10) for an EV (here and now). I'm not too sure the Clio can really manage 600 miles nowadays but it is a good 15 years old!

If I have to use a motorway/commercial charger then the cost is around £0.50 to £0.80 per kWh (https://www.gridserve.com/electric-vehicle-charging/our-pric...) I don't use them very often

The EV will need a new battery in around four years time, or I pass it on.

ICEs are around 150 years old. I went to school in Abingdon, where the Morris Garage (MG) operated from in about 1930(?/ish). My MG is a Chinese effort and about as British as I am. EVs are at about the stage that ICEs were when a bloke had to walk in front with a red flag.

> Oh and I pay £1.28 per litre and 7p per KWh (for overnight car charging). The petrol price is low at the moment for here (it hit £2+ when Russia went mental).

I (in the US, California) pay less for petrol than you and more for electricity; 87p/L and 23p/kWh overnight.

That might be where the EV wheels fall off!

CA is notionally EV friendly but it is also a US state and it is rather large, so range is king. CA is mostly very warm so that helps with range. Gas (petrol) is relatively cheap and 'leccy is quite expensive.

The UK extracts rather a lot of tax (fuel duty) on top of the actual market cost of petrol. That's why our petrol/gas cost is pretty extreme. I have no idea how we ended up in this pickle (I have a few ideas), given that we have the North Sea oil deposits nearby. I think we failed to work that as well as Norway did. Bloody amateurs!

You probably have rather more land than me and could consider solar cells. My house conveniently faces south but its a two storey bungalow with three dormers, which means I can't put PV cells on the roof, facing the sun. My garden is also rather unsuitable for PV, being about 1/2 acre with mostly a 30% slope (its quite odd).

The world's climate woes are not yours or my responsibility. PV and EV may help or not. I can manage EV but not PV. You may find that the capital cost of deploying PV in CA might pay off quite quickly.

My IT company has a customer ... . They have a PV (solar panel) deployment on top of a building. This is in Dorset (UK). There are something like 20-30 panels on the roof. I've seen the monitor on a fairly bad day - 2 KW and in bright sunshine something like 8 KW. I'm pretty sure that CA could do rather better.

My total lot is under 5000 square feet (about 450 square meters), much of which is covered with house. I do have rooftop solar.

A few other notes:

- On average, both petrol and electricity is more expensive in CA than most of the US

- Petrol is expensive throughout the state, but electricity can be cheap if you live in a city with public utilities (The city of Sacramento has a public utility and rates are about half what they are on a private utility where I am).

- Peak rates are about $0.55/kWh (41p), but off-peak times are a generous 19 hours a day 21:00-16:00) in the summer, mainly because there is so much solar, so we have the "duck curve[1]" here.

- I live near the coast, so get fog in May and June, but July and August I generate quite a bit (over 10kWh per day this July).

1: https://en.wikipedia.org/wiki/Duck_curve

You note that you have rooftop solar - how is that going?

I'd love to deploy it but the south facing side of my house has three dormers on it which means: I'm stuffed. I can't fit panels on a 12m (40') long roof, with inclusions.

I wish you all the best, mate.

You're highlighting something that's not relevant. The people who are abandoning their EVs are doing so in spite of the tremendous savings. That should raise alarms.

Tremendous savings? I save less than 10% charging at home, at off-peak, vs a Prius for highway driving (3.8mi/kWh vs 50 miles/gallon):

  You have: (0.28USD/kWh)/(3.8miles/kWh)
  You want: USD/mile
   * 0.073684211
   / 13.571429
  You have: (4USD/gallon)/(50miles/gallon)
  You want: USD/mile
   * 0.08
   / 12.5

There are 3.8 litres to the US gallon. You pay $4.00 per gallon and I pay 3.8 * £1.30 = £4.94. I remember the days when it seemed like fuel was almost free in the US compared to here!

Your electric rate looks high at $0.28 per kWh. Its still less than I pay in general - £0.287 but I get an overnight rate at £0.07 (23:30 to 05:30).

It seems reasonable to have a low rate at night and always has been. In the UK it used to be known as "Economy 7" (seven hours not 7p!) That's nothing new and I remember it being a thing from the eighties. I'm surprised you don't have something similar.

I misremembered the cost for electricity; it's $0.26 not $0.28 (and that is the discounted overnight rate). Peak usage is over $0.50, but that's only 4pm-9pm in the summers.

The bill is rather maddening because there is no one place where they put the price per kWh. There is "Delivery Cost" "Generation Cost" and "Non bypassable charges" each with different values for peak/off-peak so I have to do the math myself.

Bloody numbers! I also have snags dealing with them and I have an A level in Maths.

Your discount rate at $0.26 - I assume that is for overnight usage - sounds a bit nasty. Are you able to move to another provider or are you tied to a single provider?

If the latter, then that is another discussion 8)

Basically one provider.

More details: All but the generation charges are from a single company that (among other things) is paying off a lawsuit for having not properly maintained lines running through highly flammable forests.

The generation charges can com from two companies; one has a slightly higher sticker-price, but discounts down to what the other charges, so the rates are identical.

I had my overnight electricity rate wrong it us $0.2608 which makes it about 6.8 cents per mile vs 8 cents.

agree

here on the other coast, with cheap gas and expensive electric, Prius would be about 6 cents/mi, Bolt costs me about 8 (on average winter/summer)

gas is $2.80/gallon, electric (with off peak program) $0.30/kWh. Bolt (fairly efficient EV) 3.8 mi/kWh (3.4- Winter 4+ summer)

Yup, in CA with PG&E a gas car is cheaper to drive than EV unless one has solar or free charging at work.

sure but here's an example from my mazda 3. after 17 years it exceeded it's rated range . the original full tank range was 337.5 miles. After 17 years i was getting 398.25 miles

With EVs you have a massive loss of utility over just a few years . Going from 337 miles to 320 miles in the first year is a huge loss. and down to 269mi after 10 years is catastrophic

> 269mi after 10 years is catastrophic

I have taken multiple 1000+ mi road trips with great ease on 280mi range. I would describe it as the exact opposite of catastrophic. And they've only become easier since then (e.g. more charger deployments).