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Specifying shorter range

Posted: Sun Aug 05, 2012 9:06 pm
by NeilK
Before I look a complete dork in public I thought I'd pitch this one on the Forum to see if there has been earlier conversation on the subject of specifying cars with even more limited range than is common. (I am new to the Society)

The thinking goes like this: I live on an island and I drive 8 miles to work. On a big day I may drive 50 miles, but that will involve being parked for several hours at locations with charging points. I am unlikely to need a car that will do more than 50 miles on a charge. So has anybody spoken to the manufacturers and asked for this to be an item one can specify.

It seems odd that I can get pointless items like the paint colour specified or the wheel trims in a ICE car and I can specify the engine size or way the roof folds up, but I cannot specify the size of petrol tank in it. Obviousy no-one ever asks, so range is a function of 'economy' not volume of fuel carried.

If an EV is basically 3x the cost of an average ICE vehicle of the same size then is it fair to assume that the additional 200% is probably the battery cost? (the engine and electic motor probably being comparable). So if I asked for a half size battery then would that reduce my vehicle costs by 1/3? Has anybody tried this on with the manufacturers?

If anybody has got any comment or suggestion then I'd be glad to hear.

Thanks,

Neil

Re: Specifying shorter range

Posted: Sun Aug 05, 2012 9:15 pm
by Kevin Sharpe
NeilK wrote:If anybody has got any comment or suggestion then I'd be glad to hear.
Renault Twizy

Re: Specifying shorter range

Posted: Mon Aug 06, 2012 3:06 pm
by timpootle
Up until very recently, what was offerred was less than anybody wanted.

The new Tesla S can be specified with 3 different batteries (160 miles, 250, 300), so that is getting to the way you are thinking, but for the Nissans and Renaults of this world I think the answer is no. The battery is a major part of the car design and they couldn't fit a smaller one even if they wanted to.

But you could. I'm guessing you don't want to get your hands dirty as you have mentioned speaking to manufacturers. There are still low-range cars available in the quadricycle class (Gwiz, Mega-City, that sort of thing) or as Kevin says, the shiny new Twizy. It really depends how much room you need, weight you will carry, that sort of thing.

/2p

Re: Specifying shorter range

Posted: Mon Aug 06, 2012 6:11 pm
by GregsGarage
Another consideration with short range vehicles is the stress on the battery pack. The pack will be working harder relative to its size, so cells that work fine in a long range pack could have their life cut considerably when worked harder in a short range pack.

Re: Specifying shorter range

Posted: Mon Aug 06, 2012 6:46 pm
by NeilK
Kevin, Tim & Greg,

Thanks for your replies. I think the Tesla is out of my league... unless the lottery comes up this week.

Interesting about the Twizzy: you can specify colour, but not doors! They really do seem to be too much of a toy. G-Wiz is in the same league I'd say, but without the manadatory air flow of the Twizzy.

I hadn't looked at the Mega City, but will have a bit of poke about for one.

As to the issue of smaller battery packs meaning more battery stress: Interesting point and I hadn't seen it from that point of view. Is this an issue across the range of battery materials or are there any sweeter materials?

I am also assuming that the reduction in batteries would have a decent weight saving too. I also cannot believe it can be that hard to tell a bloke on teh production line NOT to stick something into the car if that option has been designed in.

Whilst typing there is a fascinating TED talk by Amory Lovins on car efficiencies and it goes something like this:

5/6 of the chemical energy in petrol does not make it into anything useful. The rest goes into heat and noise. Of the 1/6th (=13%) around half (6%) goes into heating up the tyres in rolling resistance. 1% goes into warming the air as it is being pushed apart to drive the car through. The remaining 6% moves the car and is turned into heat in teh brake pads. ..... but only about 1/20th of the car is the driver. The rest is metal and soft furnishings. So only 1/20th of the 6% that is being useful is doing the intended job of moving the driver from A to B. :oops: So in terms of the big savings the 2 areas are the fuel conversion efficiency and the weight of the car which I assume is no surprise to anybody here, but it sure will be to the general public!

Finally; in terms of getting my hands dirty..... that is about to start, so watch this space!

Neil

Re: Specifying shorter range

Posted: Mon Aug 06, 2012 9:40 pm
by GregsGarage
I think doors are optional on the twizzy, so you can get them.

Nimh are proven for use as small battery packs that can handle high C rates which is why you find them in hybrids. Sadly they are hard to get hold of and trickier to charge properly.

Renault with the Twizzy and the rest of their range of EVs are trying to get round the problem of the cost of a battery pack by leasing it. Your lease costs depend on how much range you require. The Zoe is supposed to be out end of the year (or early next year) if you need a real car.