Fast charging anyone?

[pgk pgkParticipant @pgkpgk17461]

Israeli Co Lithium tech

[pgk pgkParticipant @pgkpgk17461]

Store-Dot

https://www.store-dot.com/ev

pgk

[not done it yetParticipant @notdoneityet]

At the right cost and reasonable longevity, that would end the harping about those two factors regarding BEVs.

[Speedy Builder5Participant @speedybuilder5]

Yes, and just imagine the chaos as all roads are ripped up to triple the load capacity of the existing power cables. Electric cars, electric heating etc etc as gas oil and petrol etc convert to electricity – and then the electricity workers go on strike for more pay. Its a case of all yer eggs in one basket??

[Russell EberhardtParticipant @russelleberhardt48058]

Hmm …

5 minute charging time for a Tesla S 60 battery will require 720 kW from the supply, not allowing for charging inefficiency. So, if a standard 240 V supply is used, it will need to supply over 3000 A. So how thick will the cables be? A motorway service station might need 10 charging points so it will need a 7 MW supply at peak times!

Russell

[not done it yetParticipant @notdoneityet]

Posted by Speedy Builder5 on 19/01/2021 09:11:45:

Yes, and just imagine the chaos as all roads are ripped up to triple the load capacity of the existing power cables. Electric cars, electric heating etc etc as gas oil and petrol etc convert to electricity – and then the electricity workers go on strike for more pay. Its a case of all yer eggs in one basket??

So what did you do when the tanker drivers went on strike? What did you do when the oil crises of the early’70s occurred?

Charging stations would store leccy, just like they currently store petrol? Only they would just need to store it on a daily basis? Taking power for three times as long, instead of three times as much, is the simple answer to your stifled imagination!🙂.

‘On yer bike’ would suffice for a fair amount of the mileage covered by many current car users (thinking here of the daily school run, minor shopping expeditions, etc)

Whatever happens, there will always be a residual group of carpers.

[Ady1Participant @ady1]

We'll get there eventually but batteries are very variable in quality

Even at the AA level the only decent ones tend to be the eye wateringly expensive ones

[Dave HalfordParticipant @davehalford22513]

Might be the answer for lorries with a high voltage charger

[pgk pgkParticipant @pgkpgk17461]

Requirements for fast charging can easily be dealt with – the tech is already around with plenty of 200KW DC chargers and a few theoretically capable at 350KW. The simplest lorry solution already available is 2 charge ports and charger cables with inbuilt coolant lines because of limitations of charge connectors. Home A/C solutions don't need to have that capability since they can be run overnight.
If this newer tech proves itself on charge cycles and longevity then the concept of stopping for 5min 300 mile range top-up takes pressure off charger availability en route. Note that largest european fast charger station has 42 chargers and some UK ones are now 24 bays. A motorway services carpark with 100+ chargers is likely perfectly feasible with high voltage power lines and local 'sub stations'.

Someone wiser than myself once stated that if it doesn't breach the laws of physics then it can get done.

pgk

[VicParticipant @vic]

I’m waiting patiently for the guy on here that drives 500 miles every day towing a caravan. Every forum has one when the topic of EV’s comes up.

[Robert Atkinson 2Participant @robertatkinson2]

Assuming no losses charging a 50kWh (small-medium EV) battery would need a 480A 415V 3 phase supply. per charger That is 24 houses worth of supply per car.

Storage has been mentioned but it still needs to be charged, no use for a typical fast charge senario of a motorway service area running 24/7. Not sure what storage technology can deliver 600kWh (50kW in 5 minutes) though.

Also no actual hardware, just hype. They announced start of producton of Flash batteries for phones a couple of years ago but I don't see any on the market…….

Robert G8RRPI.

Edited By Robert Atkinson 2 on 19/01/2021 13:24:50

[Ady1Participant @ady1]

Right enough

If they get them sorted the first market for them is likely to be phones to get some cash rolling back in

edit: There was also that issue where laptops were becoming firelighters on aeroplanes. They can pack an amazing amount of energy into a little block of chemical nowadays

Edited By Ady1 on 19/01/2021 13:33:01

[VicParticipant @vic]

This setup says it can add 200 miles in a 20 minute charge.

**LINK**

[Clive FosterParticipant @clivefoster55965]

Ignores the energy losses in the charging process.

Fast charging is inevitably more lossy than slow charging. Battery temperature rise during charging has always set the hard limit for how fast you can charge.

Probably something at least equivalent to 10 kW on a 5 minute charge of a 50 kWhr battery. Mostly generating heat fairly deep inside the battery too so cooling will not be trivial. Cooling is why Tesla battery packs are lots of small cells and relatively space inefficient.

Objectively Aluminium-Air is probably the best technology for reliable, simple, fast charging at rates equivalent to filling a petrol tank. But they are consumable primary cells so you can just haul the old ones out and swop a new set in. The energy storage density is very high so it could be practical to use several "200 – 250 mile rated" units per vehicle. If you had 5 units in your car planning to generally swop 4 at a time gives you a decent margin to fit the change in. The issues with aluminium-air is making them economically re-cycleble which means getting high efficiency without unfriendly chemicals and very pure metals.

If Elron gets his green rocket fuel generation system working adequately efficiently to produce hydrocarbons by cracking atmospheric CO2 and water this whole BEV thing will start looking like an early adopter fiasco of similar order to CFC bulbs. If you want to cart significant amounts of portable energy around hydrocabons beat the pants of everything else. We already have effective ways of storing and handling hydrocarbons as well as efficient ways of burning them to release the energy.

Clive

[J HancockParticipant @jhancock95746]

What am I getting wrong here ?

Easy near enough round figures.

This/any electric car is traveling 240 miles on a charge of 60kwh = 4miles/kwh

Now, to travel at 60mph in any car requires , say, 40bhp or 30kw at the wheels, flat road.

So, to travel 240 miles you will consume 4x 30kwh = 120kwh= 2miles/kwh

[pgk pgkParticipant @pgkpgk17461]

Posted by J Hancock on 19/01/2021 14:49:07:

What am I getting wrong here ?

Easy near enough round figures.

This/any electric car is traveling 240 miles on a charge of 60kwh = 4miles/kwh

Now, to travel at 60mph in any car requires , say, 40bhp or 30kw at the wheels, flat road.

So, to travel 240 miles you will consume 4x 30kwh = 120kwh= 2miles/kwh

My (ancient tech after 2.5yrs) Tesla S will do 70mph on a flat motorway and windless summer months at 300w/mile or as bad as 500w/m in winter on hilly terrain at variable speed with the heater on. The latest Model 3's will run around 50 w/m less usage (real world 300 miles on a 75KW pack in OK conditions)

pgk

[J HancockParticipant @jhancock95746]

That's where I find the figures hard to believe.

A Tour de France cyclist just about manages to achieve that output , with nothing like one tonne of metal to hump about at 60mph.

[J HancockParticipant @jhancock95746]

Real question.

Why /how can it only take 500w/mile to propel a Tesla at 60mph when a petrol/diesel has to output 30kw to achieve the same speed, with the same weight,,tyre,,bearings/rolling/wind resistance,etc ?

[old martParticipant @oldmart]

That 500w/ mile could be per mph, then 500 X 60 = 30000w. That would be 30Kw at 60 mph.

pgk pgk's Tesla at 70mph in ideal conditions would require 21000w, about 28hp at the wheels. The car should be pretty aerodynamic and the figures are feasible.

Edited By old mart on 19/01/2021 17:21:07

Edited By old mart on 19/01/2021 17:21:34

[pgk pgkParticipant @pgkpgk17461]

Posted by J Hancock on 19/01/2021 16:19:38:

Real question.

Why /how can it only take 500w/mile to propel a Tesla at 60mph when a petrol/diesel has to output 30kw to achieve the same speed, with the same weight,,tyre,,bearings/rolling/wind resistance,etc ?

300w./m and very heavy carting the pack about too…
..perhaps to do with the drive units being (almost) attached to the wheels instead of going through clutches, gear boxes and prop shafts???
Also some clever jiggery-pokery with fore and aft drive units adjustng their power proportions (as they do) during cruise and of course reharvesting braking energy when available

pgk

[duncan webster 1Participant @duncanwebster1]

watts per mile is a bit of an odd unit, I'm not sure it means anything.

According to the interweb it takes 15-20 kW for an average car to cruise at 60mph, this is 250 to 300 Watt hours per mile, so perhaps that's what pgk's unit should be

converting CO2 and water into hydrocarbon fuel won't get over the NOX problems in inner cities, but it would be a very good start.

[Maurice TaylorParticipant @mauricetaylor82093]

Posted by pgk pgk on 19/01/2021 17:22:35:

Posted by J Hancock on 19/01/2021 16:19:38:

Real question.

Why /how can it only take 500w/mile to propel a Tesla at 60mph when a petrol/diesel has to output 30kw to achieve the same speed, with the same weight,,tyre,,bearings/rolling/wind resistance,etc ?

300w./m and very heavy carting the pack about too…
..perhaps to do with the drive units being (almost) attached to the wheels instead of going through clutches, gear boxes and prop shafts???
Also some clever jiggery-pokery with fore and aft drive units adjustng their power proportions (as they do) during cruise and of course reharvesting braking energy when available

pgk

Hi ,please correct me if I’m wrong but shouldn’t the unit per mile be “Wh” ,I think this is were any confusion is coming from.

Maurice

[VicParticipant @vic]

**LINK**

Obviously we don’t know how Tax changes will effect EV’s in the future but not much we can do about that.

The same as we can’t stop them putting up road tax on Diesels to £2000 a year from 2022.

[J HancockParticipant @jhancock95746]

MT, yes, you are right that the units should be Watt hours but the principle Laws of Thermodynamics seem to be not applicable to this new form of transport ie something no more powerful than your Super 7 motor is powering a tonne+ of car along at 60mph..

This is truly amazing.

[Maurice TaylorParticipant @mauricetaylor82093]

Posted by J Hancock on 19/01/2021 18:09:48:

MT, yes, you are right that the units should be Watt hours but the principle Laws of Thermodynamics seem to be not applicable to this new form of transport ie something no more powerful than your Super 7 motor is powering a tonne+ of car along at 60mph..

This is truly amazing.

Hi,I’ve worked it out ,I think. Car travelling at 60mph using 300Wh per mile will use 0.3 x 60 =18kWh to do 60miles.

This means an 18kW motor is needed (18kWh divided by 1h).

Then I googled power needed to keep a constant speed of 60mph this was19kW.

Please somebody correct if wrong.

Maurice

Edited By Maurice Taylor on 19/01/2021 19:44:15

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