fiver for a 20 minute fast charge strikes the right balance

treemachine

Martyn1981 wrote: »

Think about it this way, a 2kW generator will take one hour to generate 2kWh.

An EV can get about 4 to 6 miles per kWh, so at best, the 2kW charger will move the car 12 miles in 1 hour. Therefore, you'd be looking at 12mph.

That's probably a dangerous speed, so if you had 12 miles to go, you'd have to stay put, generate 2kWh, then drive home at a safer speed.

Mart.

Hi Mart,


Perhaps, I should have made my point clearer. I think a small generator could be used to "help" power an electric vehicles on long journeys (in addition to the battery). I certainly wasn't advocating trundling along at 10mph on a motorway.


We all know that most car trips are mostly local journeys where an electric vehicle would be suitable. However we also know that people don't buy electric vehicles because they are not suitable for long journeys. Having a removable petrol engine (s) would mean the main disadvantage of electric cars is partially overcome.

EricMears

treemachine wrote: »

Hi Mart,

Perhaps, I should have made my point clearer. I think a small generator could be used to "help" power an electric vehicles on long journeys (in addition to the battery). I certainly wasn't advocating trundling along at 10mph on a motorway.

We all know that most car trips are mostly local journeys where an electric vehicle would be suitable. However we also know that people don't buy electric vehicles because they are not suitable for long journeys. Having a removable petrol engine (s) would mean the main disadvantage of electric cars is partially overcome.

If you were doing 100 miles on a motorway - e.g. Heathrow to Birmingham airport would be 102 miles of practically all motorway - it would take around 1h 40mins. Keeping a 2kW generator running for that time would give you an extra 3.3kWh which might extend your range by up to 12 miles. (In my particular case it probably wouldn't be able to use all of the 3.3kWh)

That might make such a trip possible for me in that my 'normal' 90 mile range wouldn't be enough but an extra 12 might just swing it. However, I'd never in a million years entertain the idea ! The generator would need to be secured in place and some provision made for venting the exhaust fumes. My normally quiet environment would become far noisier than an ordinary ICE vehicle and I'd lose three quarters of my normal luggage space.

For anyone who really wants that sort of facility, the BMW Rex is worth considering. But that's a properly installed 650cc engine which adds around £3000 to the price of the car. Even that's not without problems though - there seems to be a known issue that if the car is driven on a flat battery with the Rex running it's likely to slow right down to 45mph (less on hills). See http://www.greencarreports.com/news/1104072_bmw-i3-rex-electric-car-lawsuit-range-extender-power-loss-alleged

Even £6 for a half hour top-up at a motorway service station (which would definitely make such a journey possible for me) would be somewhat cheaper than putting up with the inconvenience, buying a gallon of petrol and suffering the extra loss of interest on the purchase price of such an engine.

zeupater

... as well as the fumes likely resulting in trashing the car, yourself and others .... it's simply a case of understanding the limitations of the various offerings and selecting the most suitable technology for your needs ...

Z

Martyn1981

treemachine wrote: »

Hi Mart,


Perhaps, I should have made my point clearer. I think a small generator could be used to "help" power an electric vehicles on long journeys (in addition to the battery). I certainly wasn't advocating trundling along at 10mph on a motorway.


We all know that most car trips are mostly local journeys where an electric vehicle would be suitable. However we also know that people don't buy electric vehicles because they are not suitable for long journeys. Having a removable petrol engine (s) would mean the main disadvantage of electric cars is partially overcome.

Hiya TM. Don't worry, I get where you are coming from, and with respect (honest) I love strange and whacky ideas, as they often lead to something great.

The problem here isn't whether it would work, which of course it would. But is it practical, safe and legal. I'd also wonder about the cost as it would probably burn a lot of petrol. So I don't think it's a goer.

Maybe we'll see mobile generators, a bit like the guys who go out when you put the wrong fuel in. They come to your car, then charge it up a bit ...... mind you, they could just tow you to a charger ..... damn, shot my own idea down there.


Here's my whacky idea of the day. How much depreciation does 1 mile of motoring cause?

On newer cars I seem to remember it being 10p/mile, but I may be wrong. The reason I ask revolves around the economics of hire cars.

Let's say you need to do 300 miles in a day, your EV can't do it, and it'll cost you £30 in hire costs. Would the 300 less miles on your car save you £30 in depreciation. This also applies to ICE cars too.

There would also be savings on fluids, tyre wear, and servicing costs (as you'd be 300 miles further away from the next service).

Just a thought, as it occurred to me that hiring a car isn't necessarily a duplication of costs. And you could hire the best car for the trip, rather than what you own, which is usually the best compromise for all purposes. So you might hire a tiny car, to save on fuel costs, or a 7+ seater for a big getaway etc etc.

Mart.

almillar

Real world numbers always are.

My Zoe is looking at around 3.5miles/kWh in winter and just about 4.5miles/kWh in summer - mostly used for commuting, I'm not scared of doing 70 if I need to but rarely get the opportunity. I could go faster if I wanted a lot of the time, but I could also be more economical a lot of the time. You really do need to run an EV all year to see the big difference in range.