Electric vehicles miles per KWh

JKenH

GreatApe wrote: »

I wonder if it would be wise for a BEV like a model 3 to have an option to split it's battery pack

So instead of a 50KWh battery pack in the car maybe a 30KWh pack in the car and a small compact 20KWh pack towed behind with the ability to very easy attach or detach this additional pack

The idea being an owner could keep this additional 25KWh at home most the time and only attach it to the car for when they are doing more than 125 miles.

I think something like that would make a model 3 more interesting

For the same price you get a huge 20KWh home battery pack that you can use as a Tesla power wall plugged into your home

And for most of your daily commute your car would be lighter and more efficient

I think something like this could also normalise lower range EVs
With people realising they can leave their 20KWh towable pack at home almost constantly maybe they would be fine for their next EV to be only 120 mile range

Towing is a huge handicap to mpg so I would imagine it would be to a BEV’s consumption. It is also an absolute pain finding somewhere to park a trailer on your journey.

GreatApe

1961Nick wrote: »

With an annual mileage of 33K it's going to save me a lot of money....and that's even before all the taxation incentives.

Early adopters of the performance model are reporting a real world range of around 240 miles.....which is probably representative as hypermilers are unlikely to go for that derivative.

If you do that many miles I think you'd benefit from it much more than a normal driver

Get the 7KW charger they seem to be £300-500
Almost all your charging can be done at off peak 4h rates
You might be able to recharge 100 miles during those four hours
So your paying for the first 100 miles the cheaper off peak rate and then any mileage over that the normal tariff

It doesn't matter if you charge a few hours outside of this 4h cheaper window the bulk will be in the cheaper window

EricMears

Dave_Fowler wrote: »

The Ioniq has a set of regeneration paddles on the steering wheel which you can use to slow down during normal driving, so the excess energy is used to recharge the battery rather than heating the brake pads. This as a side effect reduces pollution from brake dust as you rarely have to use the brakes. Also, as some of the energy used to accelerate is fed back to the battery, carrying extra passengers or heavy loads does not reduce fuel consumption as much as in a conveniional ICE car. Stopping and starting in town traffic or waiting in a traffic jam has a much reduced penalty on consumption.

Dave F

Useful as regenerative braking is, it really isn't 100% efficient (or probably even 50% !). But of course even that is a lot better than an ICE car where all braking is wasting energy.

Afraid one of my 'niggles' with the Leaf is that some misguided programmer has decreed that the car will always apply regenerative braking as soon as I stop accelerating. As a result where I would lift my foot off the accelerator pedal when driving an IC engine vehicle and let speed build up a bit going downhill then let gravity do its work by slowing it down gradually going up the next hill before applying acceleration halfway up it, doing that in a Leaf results in the car applying regenerative braking going down the hill and maybe even continuing to do so when going uphill. Really not helpful to economy ! I was a lot happier in that respect with my previous EV (a VW e-Up!) which behaved much more like Dave describes.

EricMears

JKenH wrote: »

Towing is a huge handicap to mpg so I would imagine it would be to a BEV’s consumption. It is also an absolute pain finding somewhere to park a trailer on your journey.

Also worth mentioning that very few BEVs are type-approved for towing !

Martyn1981

EricMears wrote: »

Useful as regenerative braking is, it really isn't 100% efficient (or probably even 50% !). But of course even that is a lot better than an ICE car where all braking is wasting energy.

Possible solution/improvement to that issue would be to add a very small amount of storage via an ultra-capacitor, a bit like the ones Maxwell makes (the company Tesla recently bought).

These can charge or discharge at massive rates, so just 1kWh would work for very hard acceleration and hard regenerative braking, it would also reduce the hardest power demand on the battery during those few seconds. If you remove the hardest load from the battery, then you'd most likely reduce battery damage/degradation.

As a bonus, you wouldn't need such large battery packs for high performance. I'm assuming there is no rational need for 600+ miles of range for the Tesla Roadster II, so the massive battery (200kWh) is needed to provide the massive (but brief) power demand that its performance stats require?

GreatApe

JKenH wrote: »

Towing is a huge handicap to mpg so I would imagine it would be to a BEV’s consumption. It is also an absolute pain finding somewhere to park a trailer on your journey.

I think you're imagining something big and bulky

It might be better thinking of it as an attachment to the rear so carried by the model 3 something like an additional bumper making the car 20cm longer. Designed nicely

TBH I don't think it's a great idea

Better for Tesla and the industry to just offer a smaller 25KWh 125 mile range smaller EVs at more affordable prices. And ideally BEVs at the sub £15k mark with 120+ miles range

JKenH

GreatApe wrote: »

And ideally BEVs at the sub £15k mark with 120+ miles range

I wish there was a better choice of small BEVs available as I am sure that would suit a lot of people to have one as a commuter/second car/runabout. After all EVs make far better city cars than ICEVs and small cars are better city cars than large ones so why are so few small BEVs available? The charging regime for a small second car would work well for those with solar panels but no battery.

I keep looking at the E-up but it is ridiculously expensive for a small car. I am waiting for Kia/Hyundai to come up with one to replace the Picanto/i10 but whenever I enquire I am told there is nothing in the pipeline.

EricMears

JKenH wrote: »

I wish there was a better choice of small BEVs available as I am sure that would suit a lot of people to have one as a commuter/second car/runabout. After all EVs make far better city cars than ICEVs and small cars are better city cars than large ones so why are so few small BEVs available? The charging regime for a small second car would work well for those with solar panels but no battery.

I keep looking at the E-up but it is ridiculously expensive for a small car. I am waiting for Kia/Hyundai to come up with one to replace the Picanto/i10 but whenever I enquire I am told there is nothing in the pipeline.

Our first BEV was an e-Up!. It was an ex-demo with around 200 miles on the clock and cost £15k (not quite sub-15k but very close). Nominal range was 90 miles though I was never very confident of getting more than 70 but that really wasn't a problem as we only ever intended it to be a 'shopping trolley' but even so it accounted for over half of our annual mileage.

Replaced it with the Leaf last year and it now accounts for over 90% of our annual mileage. Nominal range of 160 miles is reasonably believable but I usually arrange longer journeys to have a P&P stop every couple of hours anyway so having them at a rapid charger is no great hardship (esp not when Nissan dealers will let me charge gratis )

ed110220

JKenH wrote: »

I wish there was a better choice of small BEVs available as I am sure that would suit a lot of people to have one as a commuter/second car/runabout. After all EVs make far better city cars than ICEVs and small cars are better city cars than large ones so why are so few small BEVs available? The charging regime for a small second car would work well for those with solar panels but no battery.

I keep looking at the E-up but it is ridiculously expensive for a small car. I am waiting for Kia/Hyundai to come up with one to replace the Picanto/i10 but whenever I enquire I am told there is nothing in the pipeline.

Main problem is that with the current cost and shortage of batteries a small EV is considerably more expensive than a small ICE and therefore appears poor value to many buyers. Once you go up to larger/more expensive vehicles, the difference is proportionally smaller and so the EV appears better value.

Compare USA sales of the Tesla Model 3 for Jan-July this year at 81,000 with say the Chevrolet Bolt (9,266), Nissan Leaf (6,946) or BMW i3 (2,511). Even though the Tesla is considerably more expensive, it sells much better as it compares better with ICE vehicles in its class (which it also outsells).

It's frustrating, but I think it will be a little while before EVs really compete with ICE vehicles at the lower end of the market.

GreatApe

JKenH wrote: »

I wish there was a better choice of small BEVs available as I am sure that would suit a lot of people to have one as a commuter/second car/runabout. After all EVs make far better city cars than ICEVs and small cars are better city cars than large ones so why are so few small BEVs available? The charging regime for a small second car would work well for those with solar panels but no battery.

I keep looking at the E-up but it is ridiculously expensive for a small car. I am waiting for Kia/Hyundai to come up with one to replace the Picanto/i10 but whenever I enquire I am told there is nothing in the pipeline.

Best selling car in the UK for a very long time is the ford fiesta which can be had new for £12k even with the depressed pound.

A ford fiesta electric version (and rivals) is needed for a price point no higher than £15k and ideally exactly the same £12k for petrol

Not special deal or one off pricing but that being the norm

Such a car with 120 miles would do very well
If they could get 5 miles per KWh it would need 24KWh battery pack

Also when such cars arrive I think there would be an explosion in EV charging infrastructure

If every suitable house / business had a 7KW charger (or more) such cars could recharge at 35 miles per hour almost everywhere. Visiting grandma a hundred miles away don't worry the car will be full in 3 hours and your probably visit for longer than that anyway

Set up a system where you can connect to any charger and the car gets billed not the charger owner. So even if you go to a friends house hook up and you get billed not them.

That way 120 miles is fine for a radius of 100 miles because you can charge at both ends of the trip without the awkward 'can I use your electricity'