Another thing about electric cars

[Dave Plowman (News]

Trivial to make a vacuum squirt water. Easier than a vacuum motor?

They were OEM, made by Trico.

[Andrew]

Ditto vauxhall victors FA and FB. Maybe that was the accepted way of doing it, since it required switching a fairly high current, something that the available technology made it difficult with column switches in those days.

[Fredxx]

No reply implies once again that you make lots of suppositions without any substance.

[Fredxx]

As shown, the degradation is minimal for charging Lithium Ion batteries.

EV Batteries are cooled and temperatures measured. Charging rates are adjusted accordingly. You're not comparing like with like.

[The Natural Philosopher]

On the contrary, in my case I am moderately sceptical (not anti) of EV precisely because I have built and owned so many of them - albeit small, with wings, but EVs they still were.

Why not look at things from say my perspective, My first electric plane in 2001 barely flew on a NiCd pack. Adding a higher voltage one allowed almost 5 minutes of reasonable flight, Then in the early noughties (2004) I imported some LiPo cells from the USA and got three times the energy density., Electric flight became easy and flight times of up to an hour were possible by managing the power envelope. I threw those cells away this year - they had lost about 2/3rds of their capacity.

Now those cells were, for a long time the lightest cells for decent power that I could get, which is why I kept them.

They delivered 5.2 watt hours per ounce. Today my lightest Lipo cells delver 3.9 watt hours per ounce. Energy density has been sacrificed for safety, lifetime and fast charge. In short *in 16 years* the energy to weight ratio of the batteries *has not improved, one iota*.

Cost has however. I think I paid $10 instead of $35 for a similar pack this year.

Now putting that into a typical car battery - we really want 600 miles and today we are getting in round figures a reliable 200 out of a 80kwh battery: so we need about - let's say 250kwh.

At, say, 4 watt hours per ounce, that's 62500 ounces, 1.75 tonnes give or take, About as much as a current fuel car weighs IN TOTAL.

And my cells retail at around £0.05 per watt hour putting a 250kWh battery in the £12,000 category. And remember I am buying bare cells in a pack - no case, no cooling, no safety shit.

In short the *battery* for a reliable range weighs as much, and costs as much as a basic small fuel car complete..

And most importantly, that weight has not changed - in fact it has got

*worse* - in the last 16 years.

*That* is why I am sceptical. There is a massive pressure to improve energy to weight. And yet it has got worse!

That shows to me that there is a fundamental theoretical limit being approached here. The chemistry we are using can't do any better.

And hasn't done any better, for years.

Now the theoretical energy density of lithium in an academic sense is about three to ten times better, but in 20 years no one has found a better way of packaging it to achieve it.

It is all very well to hand wave it away with 'batteries will get better' from a position of religious faith and technical ignorance, but the fact is, in the one area where energy to weight is CRUCIAL - that is, electric flight - the manufacturers simply have not achieved any advance in 16 years.

We have to assume that in this respect batteries are about as good as it gets, and we are not going to see 600 mile ranges ever, let alone in the near future, unless a radically new approach to lithium - and lithium is the best metal by far theoretically - is developed.

And that means probably 300 miles range at most - because a heavy expensive car that drives like a truck is simply not something people will tolerate .

We are in a similar position as trying to design steam power aeroplanes, it can be done - it was done, once - but it simply isn?t as good as petrol power. Too little range, too much weight...

I don't fly fuel powered model aircraft any more. Electric is better, and the sub 60 minute flight times are no problem at all for models.

I don't drive an electric car because fuel cars are simply better. And the sub 300 mile range and lack of charging is a *real* problem.

To say that it will all get better, that electric is 'better' or that its shortcomings can be worked around, is not a rational argument. It is a religious one.

From a rational point of view BEVS are about as good now as they will ever be for at least the next ten years, and are only as good as they are due to massive and complex computer control and regenerative braking

I am absolutely not resistant to change, per se, but I am resistant to change that is enforced, for wrong reasons, on the promise it will all work out OK, when its is obvious to me that it will not.

BEVs are here to stay and I am sure will become a feature of intra urban transport.

But to legislate fuel cars away for no good reason is simply irresponsible

[Fredxx]

EV batteries are generally guaranteed, therefore it is in the manufacturer's interests to mollycoddle them.

Why you should ever think this is comparable to the placement of a fuel tank beats me.

[The Natural Philosopher]

In my case, it is simply that the cost of owning two cars - I am nowhere near a car hire place, and as you say as you get older hiring gets gritty - precludes it, and you can get very cheap diesel cars after all the hoo hah.

[The Natural Philosopher]

And no fan to blow on a radiator?

'liquid cooled' unless you have a constant supply of cold water means air cooled in reality. The liquid is just a way to get the heat to the fan blown radiator.

However am surprised. there is no great need to keep batteries at an exact temperature. Somewhere between 10 and 40 C is good enough

Blowing air on fins is enough to do that

[Andy Burns]

For AC charging the car's on-board charger is in control, limited by how many amps the EVSE will provide.

But for fast DC charging, AIUI the external charger is connected (maybe via a contactor?) to the car's battery, there is communication where presumably the car lets the charger know what voltage represents full and what's the max current it can handle?

[Dave Plowman (News]

You're hardly going to use jump leads, so assume the connector on the car for fast charging (and the charger that fits it) takes all this into account?

[Chris Green]

All cars I ever drove of that sort of vintage ('50s, '60s) had foot operated dip switches, standard cause of grinding gears was trying to change gear using the dip switch instead of the clutch pedal.

[Tim Streater]

Are there any other chemistries that have potential? If not, we are f***ed.

And it's no good saying "We can develop or discover them", no we can't. Either possible chemistries are known about today, or they do not exist.

Remember that when the Wright brothers did their thing in 1904, the only think that stood between them and the 747 was engineering development.

[tim...]

so you need to be 80 to remember one then

tim

[tim...]

Oh I know

because that was where the thread started and the comment based upon "you only need to charge your car up once a week" was the solution to not making the street scene look messy by having one charger per space

As has been explained, it's not the cost of the charged but the work to install it

unlike petrol supply, communal chargers need to be provided in excess of demand, because they can be "over occupied" by people not actually using them

[Dave Plowman (News]

I doubt it would actually be that much when geared up to do it. Think when they changed every gas appliance for natural gas. Or Virgin etc running in cables for your TV, etc.

Lot more expensive for a one off.

[Andy Burns]

Yes, it's not 12VDC, between the car and the external charger, they negotiate over a data connection to supply up to 1000V and up to 500A, though for the full whack it needs silver plated contacts and liquid cooled cable, harry's granny cable can't compete.

[The Natural Philosopher]

Lithium air, which uses raw lithium and oxygen, could be theoretically good enough

But no one has made it work yet outside a lab.

Yup. Once we have hydrocarbon fuel energy densities, flight was just a matter of engines and structures

[Tim Lamb]

In message [e-mail], bert [e-mail]> writes

And the Morgan series 2.

[Tim Lamb]

I'm not anti. Especially for the boss to use as a shopping trolley. The manufacturers seems to have added the Government discount to the asking price:-(

[Dave Plowman (News]

Reckon most UK cars had a floor dip switch at that time. They didn't have stalks side of the wheel until much later.