Will Electric Vehicles Be Viable? When?

[Just_a_fan]

What is a plug-in hybrid missing for that 200 mile trip?

i think the issue with PHEV's is that the battery-only range is generally about 20 miles. Because of weight.

The best way to do it would probably be to have an electric drivetrain and a petrol turbine charger, but i think it'd need so much investment they've decided batteries will catch up before they could get it developed

BMW had the I3 with that concept, tho just a moped engine, and they dropped it to go all BEV

Range extenders add a layer of losses that don't make sense. So they added a bigger battery and said "range is enough now, stop worrying".

A better option, where range is needed, is an ICE driving wheels directly. For the urban stuff, the EV bit is better. So the best compromise design is to use the best bits of both. Ergo hybrid.

[strad]

The system can only regency a given maximum rate. More weight plus an incline at speed might result in more energy than the system can handle.

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Really?? I would have thought there would be some kind of bypass when it started receiving more than it could safely handle. Sounds like poor engineering to me.

[Just_a_fan]

The system can only regency a given maximum rate. More weight plus an incline at speed might result in more energy than the system can handle.

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Really?? I would have thought there would be some kind of bypass when it started receiving more than it could safely handle. Sounds like poor engineering to me.

That bypass would effectively mean that regency braking was at a maximum. So any further retardation would be by the brakes. And if the brakes aren't big enough then you'll run out of brakes. Which is what was being discussed.

[Greg Locock]

Typically the motor, battery and electronics cannot handle full braking currents at high speed. For a 2 tonne vehicle at 120 kph, slowing at 1g, the brakes need to be supplying 654 kW, roughly. Designing your electrical system to handle that when the rest of the time you only need 200 kW to drive the car is a significant investment. Since most of your braking is only at 0.3g or less you don't gain much more energy for that investment.

[Zynerji]

Typically the motor, battery and electronics cannot handle full braking currents at high speed. For a 2 tonne vehicle at 120 kph, slowing at 1g, the brakes need to be supplying 654 kW, roughly. Designing your electrical system to handle that when the rest of the time you only need 200 kW to drive the car is a significant investment. Since most of your braking is only at 0.3g or less you don't gain much more energy for that investment.

This is where I always felt the FlyBrid would shine. Energy storage like memory on a computer... fast: Supercapacitor/RAM, mid: LiPo/SSD, slow: Flybrid/Platter HDD.

I know it's not allowed, but I have always felt the multi-level storage would allow for the spikes.

[Greg Locock]

Yup, mixed energy storage is worth investigating. For our solar car we looked at supercaps to do the heavy lifting, ended up with resistance wire (!).

[henry]

Tesla have announced a tow bar option for the model Y. Tow weight set at 3500 lb , 1600kg. I’ve not seen any reports of what changes there are from the Model 3 to enable that. Perhaps it’s just marketing, it’s an SUV and they tow.

[Andres125sx]

The system can only regency a given maximum rate. More weight plus an incline at speed might result in more energy than the system can handle.

.
Really?? I would have thought there would be some kind of bypass when it started receiving more than it could safely handle. Sounds like poor engineering to me.

That bypass would effectively mean that regency braking was at a maximum. So any further retardation would be by the brakes. And if the brakes aren't big enough then you'll run out of brakes. Which is what was being discussed.

I´m not sure if I got lost in the discussion. Regen braking can´t stop the car by itself so traditional brakes are needed, ok. But that´s very different to Tommy statement about induction motors being unsuited to towing as the vehicle characteristics change so regen behaviour changes.

Obviously regen will never be enough to stop the car by itself, towing or not, question is if towing can damage regen or cause some problem to the electric motor or electronics as Tommy stated, wich is the statement wich did surprise me and I don´t understand

[izzy]

Range extenders add a layer of losses that don't make sense. So they added a bigger battery and said "range is enough now, stop worrying".

A better option, where range is needed, is an ICE driving wheels directly. For the urban stuff, the EV bit is better. So the best compromise design is to use the best bits of both. Ergo hybrid.

the trouble with hybrid like that is the ICE drivetrain makes the full weight of a conventional car, so then the battery and motorgenerator are all extra weight and they're quite heavy. So the makers have to compromise and you end up with a battery range of 20 miles and it's not really one thing or the other, it's actually the worst of both as the extra weight makes it slow and thirsty in ICE mode too!

so i think BMW were thinking along the right lines with the range extender, but obviously chucking in a moped engine wasn't an efficient way of doing it, it was slow and noisy and they only put a 9 litre tank in. But an efficient range extender would be a constant speed non reciprocating thing and they don't have one

[henry]

I would think that the physical brakes on an EV need to be sized ignoring regen. If a battery is full, or near full, no regen will be possible. An EV driver at the top of a hill where the signs recommend engaging a low gear won’t necessarily be able to rely on regen for the all or part of the descent, advantage ICE.

As well as the control electronics the battery charge rate is a constraint on long period regen, such as on a hill descent. Both Tesla and Porsche are advertising 250kW charge rates but I suspect those high rates probably rely on some battery conditioning, temperature control, which can be predicted if the car is routed to a charging station but not necessarily on an open road journey.

[Just_a_fan]

Range extenders add a layer of losses that don't make sense. So they added a bigger battery and said "range is enough now, stop worrying".

A better option, where range is needed, is an ICE driving wheels directly. For the urban stuff, the EV bit is better. So the best compromise design is to use the best bits of both. Ergo hybrid.

the trouble with hybrid like that is the ICE drivetrain makes the full weight of a conventional car, so then the battery and motorgenerator are all extra weight and they're quite heavy. So the makers have to compromise and you end up with a battery range of 20 miles and it's not really one thing or the other, it's actually the worst of both as the extra weight makes it slow and thirsty in ICE mode too!

New hybrids are achieving 40 miles pure electric on WLTP (so likely it is achievable by owners). That's enough for a good chunk of people in the UK to commute to / from work, or go to the shops / pick up the kids.

Take Land Rover's latest offerings - they give 40 mile electric only range and have a 1.5litre petrol giving just under 200bhp. That coupled with the electric motor gives nearly 400bhp equivalent. So it is quick when needed, zero emissions when needed, has the convenience of long range when needed. The best of all worlds. This performance will only get better as battery density increases.

[izzy]

New hybrids are achieving 40 miles pure electric on WLTP (so likely it is achievable by owners). That's enough for a good chunk of people in the UK to commute to / from work, or go to the shops / pick up the kids.

Take Land Rover's latest offerings - they give 40 mile electric only range and have a 1.5litre petrol giving just under 200bhp. That coupled with the electric motor gives nearly 400bhp equivalent. So it is quick when needed, zero emissions when needed, has the convenience of long range when needed. The best of all worlds. This performance will only get better as battery density increases.

Oh yes so i see. Those are pretty impressive numbers i have to admit!

[Just_a_fan]

I see hybrids as acting as the bridge to take people from ICE-only to EV. I reckon that as the hybrids improve their battery-only range, people will become more comfortable with the whole idea. Then they will realise that range isn't an issue. Of course, it also buys time to allow rapid charge infrastructure to be pushed out around a country.

On another forum I frequent, a chap has a plug-in hybrid. For his use, he has found that he uses a tank of fuel over a long period. This is because all the short local stuff is done on battery. He's filling up a small fuel tank less than once a month where previously it would have been once a week with a bigger tank.

To smack people with a "you're all having EV and you get no choice" is the best way to get a mass movement against progress. Hybrids take away the sting of change. It's all about managing people and their expectations. A bit like boiling frogs...

[nzjrs]

Take Land Rover's latest offerings - they give 40 mile electric only range and have a 1.5litre petrol giving just under 200bhp. That coupled with the electric motor gives nearly 400bhp equivalent. So it is quick when needed, zero emissions when needed, has the convenience of long range when needed. The best of all worlds. This performance will only get better as battery density increases.

Oh absolutely. I'm very very very tempted to buy one of these (I test drove one, and then the world went to ---)

[strad]

I thought you were saying that it would create more charging than the system could safely handle.