fast charging

Post by **acmotor** » Sun, 29 Apr 2007, 23:19

There is an obsession with fast charging where people want to be able to 'fill' their car in 10 minutes.
This is presumably to make it comparable with their IC motor vehicle in use. (see post on changing habits and expectations)
The problem is not in making the battery technology able to charge in 10 minutes (consider Lithium nano phosphate or super capacitors) but in having the wiring / switching and source of this energy able to handle the required rate.
Consider a 35kWh battery pack of say 350 Volts. If I were to charge it in 10 minutes it would require a current (assuming 100% efficiency for now) of 600 Amps at the 350 Volt or so. Now my house has a 50 Amp 240 Volt feed so a plug in electric with 10 minute charge would be pointless (If I were to charge it in 3 hours then I still couldn't run the kettle for a cuppa while I waited).
O.K. so I could have some other energy storage unit at home that I dumped from, but then I would need 600 Amp connectors and wiring and switches.
Maybe this high rate design is so we will be forced to fill up at service stations who are set up for the high current charging. The oil companies hate the idea of losing us.

Post by **BjBlaster** » Wed, 16 May 2007, 07:17

I think it is to do with awareness of the average consumer. This is touched on in the movie "Who killed the Electric car" where they interview people and ask them if they would drive an electric car. The answers just prove that the "average joe" bunch of people, think that the car should be fillable fast just like their ICE car. Instead they should be looking at how far do I really need to drive in a day, and design the car to run for that amount of time on a charge - otherwise drive a "plugin" hybrid - where they can drive around, do the shopping, whatever and charge it at night off peak and if they need to visit aunt hilder in Mandurah then they don't have to worry about going flat half way there because they still have an ICE in there for backup. I don't think we are really ready (peoples habbits) to go pure electric yet, some of us are but not all. I can live with a car that can get me to work and back and then I charge it when I get home

Post by **Rob M** » Thu, 17 May 2007, 17:42

The inconvenience of continually plugging in the charger to keep the batteries as fully charged as possible also needs to be considered. Keeping lead acid batteries fully charged prolongs their life and enables longer journeys during the day. I plug in and unplug the Triton ute at least 3 times per day. It doesn't sound much but it is an inconvenience. Greater battery capacity is the only real answer if we want to go totally electric. The lithium ferro-phosphate battery holds the greatest promise since it is possible to get 130km plus without exceeding vehicle gross weight limits and do not need to be kept charged to maintain longevity. The initial cost is obviously the killer but the real cost per kilometer is very likely significantly less than lead acid. Time will tell.

Post by **acmotor** » Fri, 18 May 2007, 05:25

...but if plugging into a 10Amp 240V single phase outlet is an "inconvenience" then just wait till you have a 70kWh battery pack and you have to find a 32Amp 3 phase outlet to plug into !!!!!

Post by **Plasticbrain** » Wed, 23 May 2007, 05:17

If and when we ever get to the point of having more than a handful of EVs on the road, I think charging could be done inductively at almost any location where a car was stationary for more than a minute or so... like stopped at the lights, in the car park at work, the shopping center, the McDonalds drive through, etc. The coils would be embedded in roads and car parks everywhere and the car would opportunistically draw power where available. Your car would have a transponder which identifies it to the power supplier in order to automatically bill your account.
Problem solverd.
... of course we early adopters will have to find another solution for now!

Post by **acmotor** » Thu, 24 May 2007, 04:45

Well hot diggidy doggy !
Mc Fries takes on a whole new meaning !!

Seriously though, the point is a good one. At last the parking authorities at UWA and the like will have to provide a service for the money they charge. Parking bays will have to be charging stations.

Post by **roddilkes** » Thu, 20 Sep 2007, 19:26

People often ask me how long it takes to charge my EV.
My standard answer is "10 seconds".

When they have recovered enough to respond I explain that I drive my car during the day (range 60-90km) then plug it in when I get home at night. The power cord hangs from the roof of my garage and it takes 10 seconds to plug it in and forget about it. A timer switches it on at about midnight to take advantage of off-peak power.

For your average EV fast charging is completely unnecessary.

Post by **jpcw** » Thu, 20 Sep 2007, 20:12

If you really wanted fast charging then set up your battery box in such a way that it could be lifted out of the car and replaced. You could then have two battery banks and do a quick changeover, total “charge” time about 2 minutes. Not cheap though.

[Edited to clean up non-utf8 characters]

Post by **Thalass** » Fri, 21 Sep 2007, 18:19

For most current EVs fast charging isn't really needed. But once more people start changing over to them, they're going to want to do that 500km roadtrip, or drive over to melbourne, or whatever, in their fancy new car - since it's so cheap to charge they'd save money. (It cost me nearly $678 in petrol to drive across from sydney to perth in january this year. And since it was fully loaded, I was getting about 300km to a tank! (average is 534 between fillups, though apparantly my maximum should be 634, I haven't pushed it that far yet.)

But then they'd come across the charge time problem.

I think a quick change battery would be the way to go, in the near-term, at least. You could run it like bbq gas bottles are now - you just pay for the gas (with a bit extra, of course. Need to make profit!

) and exchange the bottle. It'd take some clever design, but ought to be possible. Assuming some kind of standard could be reached, the batteries could be mass produced, and then you would just exchange however many you need during long trips, while in the city you could recharge at home (though I wouldn't be surprised if mass-produced EVs lacked that feature, so you still would have to go to the station to get your charged batteries!

)

Myself, i'll probably end up experimenting with some kind of stirling-engine generator. I have an unlimited supply of kero at work, so I could run it on that! (one of the guys at work has an old diesel VW Golf that he runs on 100% Jet A-1

)

Wow... I'm in a rambling mood today, it seems.

Post by **markrmarkr** » Tue, 03 Jun 2008, 21:15

Rod,

don't you need a separate circuit to your meter box for off-peak?

P.S.
This is my first post!!!

Post by **acmotor** » Wed, 04 Jun 2008, 06:50

That used to be the system in NSW 20 years ago as I remember.

But now, in WA at least, the modern smart meter has a clock and calendar in it. (note it does NOT adjust for the daylight saving joke that we put up with)

Your whole house can use off peak electricity by using power after 9pm and before 7am any day of the year. Currently 7.22 c/kWh

There is no separate circuit required.

There is more to the times of day, peak, off peak, high shoulder, low shoulder, summer winter etc.
See Synergy web site for more details.
[URL= ]http://www.synergy.net.au/PDF_Documents ... ak%20smart[/URL

I think it is a good system as you are in control of what time of day you charge your EV !!!!!

If you don't have a smart meter (LCD digital readout and flashing red light on the front) then they cost $170 for Synergy to upgrade.

I use off peak as much as I can and find that 60% of my consumption can be timed to be off peak. Solar HWS booster, pool pump, retic pump, battery charger etc. Aircon in the summer is a challenge though !

Post by **markrmarkr** » Wed, 04 Jun 2008, 17:40

Thats very useful to know.

The house I live in did have off peak hot water, back in the dark ages some time, but hasn't used it for years.   The electricity bills always have a spot for off peak usage which is always "zero".

So I think I must be using the old system, and it's still active. So I'll bet I can just use the off peak circuit to power the car charger when I get it going. Thats what I "was" planning to do.

But what you've said gives me another option, and if I'm wrong about the off peak circuit being active I can just do it the way you are.   In fact I'll bet it makes financial sence to do it your way anyway because it'll save money on all the other appliances and also gives me the option of charging the car during peak times without having to run two circuits (one for peak and one for off peak).

Thanks for that

Post by **Hartmut** » Tue, 24 Jun 2008, 14:53

found this under autobloggreen.com

"Electric fuel station" company gets millions of $$$
Posted Jun 23rd 2008 10:26AM by Domenick Yoney
Filed under: Emerging Technologies, EV/Plug-in, North America

One of the hurdles in the way of the widespread adoption of electric vehicles is the ability to pull into a fuel station for a quick fill-up. A "multi-million" dollar injection from Chrysalix Energy Venture Capital could very well give Dutch company Epyon just what it needs to leap over that obstacle. The company claims their technology can charge lithium ion batteries in as little as five to fifteen minutes instead of the hours it typically takes now. How do they do it? By using "state-of-the-art power conversion techniques and intelligent control systems" combined with high-power lithium ion and supercapacitor storage. The needs of each cell within the battery are evaluated and met through communication between the charger and battery management system (BMS). Also, by incorporating an energy reservoir into its system, Epyon avoids the predicament of overloading the grid with extreme demand spikes.

You won't see an Epyon station on the side of the road tomorrow though. The first thing they need to do is build some installation demonstration units and partner up with an appropriate battery company. The company, a spin-off of the Delft University of Technology in the Netherlands, plans on concentrating their initial installations in large commercial facilities such as airports or other industrial environments. Let's just hope the technology doesn't take too long to trickle down to personal vehicles since this is the kind of energy-charging solution that American electric vehicle manufacturers would seem to prefer.

[Source: Clean Break / Earth2Tech]

Post by **Richo** » Thu, 26 Jun 2008, 06:46

Would probably work well with the "CAT" bus system in Perth. They have a short set route around the cities. They could use the fast charge technique on electric busses. btw electric busses are already made and are running in other contries. Would just need to be modified for a fast charge system.
Once local councils/communites adopt them in public transport prob wouldn't be much of a leap to extend to public.
This is at least one way to get the system adopted.
You can't expect Joe Blog around the corner to do an eV conversion and hope that one day a private company or the government will put in fast charge station for him.

Not so keen of the idea of public inductive points for recharge.
Wouldn't want the kids to play in it with thier bracelets and rings!

I'd be happy with a few normal public plug in points.
My car sits at work 8hrs a day and at home 15 hours a day.
So I wouldn't really need any public charging most of the time.