Seriously thoughtful Electric Cars : BYD

[wodin]

Originally Posted by Darqref

I keep reading about the recharge time problems. It seems that to get a decently short battery charge, you need to go to a high(er) voltage and higher power level. The point about hooking your charge station directly to the power grid to avoid your house's antiquated wiring is interesting.

Is there any reasonable way to put some kind of a black box between the incoming power and the outgoing (to the car's battery) power that would change from a low(er) voltage/power to a higher voltage/power? I'm thinking of something like a super-capacitor, but the critical spec would be to allow efficient power input at low voltage, low current, and long time, but be able to discharge that black box at high voltage/ high current and short(er) time. Possibly a kinetic energy wheel, or maybe a Hydrogen/oxygen fuel cell.

The idea would be to allow either a PV cell array, or wind generator (that might not work continuously), or maybe just a regular household current from older, less capable wiring, to charge the black box. This could be done while the car is elsewhere. Then, when the car is available and needing a charge, to extract the power from the black box at high(er) speed.

If this were possible, AND it was reasonable to fuel it from a self-generated source (PV or wind or ?) then you might not care if there were extra efficiency losses in the conversion inside the black box. I know it would take a very large array to charge a car battery directly, but if you could buffer the array, would it work?

Next impossible question: make all this work in Seattle, where it's cloudy all winter.

Yes, and the technology already exists. Any home that is off the grid necessarily uses a large battery to store the power for when the sun don't shine.

The way it works is the input power, whether PV or wind or mini hydro or whatever generates a low voltage DC in the range of 24 or so volts. This is used the charge the batteries, typically lead-acid to keep costs down, then the battery output is inverted with large static inverters or motor/generator sets into AC at the required voltage and amperage to supply the house loads.

There is no reason the inverter output cannot be 440V at large amperage, except of course the high cost of the large batteries and inverter. I haven't looked into the price of batteries and inverters, but I suspect that at that scale it could easily eclipse the price of the car.

[wodin]

Originally Posted by Delta Tango

Well, the slow charge does not come from the inability of house wiring to provide high currents. It comes mostly from the battery longevity issues. In order to preserve it's capacity for many charges you need to charge it slowly.
Any house can cope with currents that would charge a car battery in couple of hours, but your battery would soon start to lose its properties.

I don't think so. An eight hour charger uses a dedicated 220 volt circuit at forty amps. That's nearly 25% of a modern home's total capacity. A half hour charge would require more than 16 times that amount, well beyond nearly any house wiring capacity. And even a couple of hours would fully load any electrical system leaving none left over to run the fridg.

[Delta Tango]

If using 25% of houses "capacity" would take 8 hours to charge the battery, using 100% would take 2 hours, which is somewhere around "couple of hours" I mentioned.

Of course, if you charge over night when the consumption is the least, it's not really important if it takes 2, 6, or even 10 hours to charge, and your fridge will have all the juice it needs.

[GeoffC]

Only 600 odd days to go .
it looks interesting, but two years down the line, one wonders the price etc....

[Steven Lyle Jordan]

Presently engineers are working on battery tech that will allow much faster charging without degrading the cells overmuch over time, denser and more long-lasting storage, and faster discharges. The technology involved in supercapacitors and ultracapacitors are seen to be the key to these processes... we may expect to see the next generation of batteries include SCs or UCs in their systems to facilitate this. Or, the SCs and UCs will be made fairly modular and added to battery systems as required.

BUT!...

Maybe we're all worrying about battery-powered cars for nothing, if Popular Science has it right!

[WT Sharpe]

Originally Posted by Darqref

I keep reading about the recharge time problems. It seems that to get a decently short battery charge, you need to go to a high(er) voltage and higher power level. The point about hooking your charge station directly to the power grid to avoid your house's antiquated wiring is interesting.

Is there any reasonable way to put some kind of a black box between the incoming power and the outgoing (to the car's battery) power that would change from a low(er) voltage/power to a higher voltage/power? I'm thinking of something like a super-capacitor, but the critical spec would be to allow efficient power input at low voltage, low current, and long time, but be able to discharge that black box at high voltage/ high current and short(er) time. Possibly a kinetic energy wheel, or maybe a Hydrogen/oxygen fuel cell.

The idea would be to allow either a PV cell array, or wind generator (that might not work continuously), or maybe just a regular household current from older, less capable wiring, to charge the black box. This could be done while the car is elsewhere. Then, when the car is available and needing a charge, to extract the power from the black box at high(er) speed.

If this were possible, AND it was reasonable to fuel it from a self-generated source (PV or wind or ?) then you might not care if there were extra efficiency losses in the conversion inside the black box. I know it would take a very large array to charge a car battery directly, but if you could buffer the array, would it work?

Next impossible question: make all this work in Seattle, where it's cloudy all winter.

If you people would stop having all that rain, you wouldn't need all those clouds.

[wodin]

Originally Posted by Delta Tango

If using 25% of houses "capacity" would take 8 hours to charge the battery, using 100% would take 2 hours, which is somewhere around "couple of hours" I mentioned.

Yes, you didn't finish reading my post. It's not strictly linear, but that is a good approximation; leaving none left over to run the fridg. And God forbid, you have an air conditioner!

[Joebill]

A rather long tiem ago, pre-1980, I bought 2 books on generating my own electricity.

The best of the two showed how to modify 3 55-gallon metal drums to make a vertical wind mill. in other words, it just would spin on a vertical axis. No need for turning into the wind before it started generating electricity. Which is a problem with the windmills with blades that are vertical.

For storing the electricity, they had 30-40 regular US 12 volt car batteries.

He said it was best to match the ampere hours as close as possible on the batteries.

But, as cheap as he claimed the setup was, I couldn't come up with a way to afford it.

[HarryT]

Nissan are also building a plant in Sunderland, in the NE of England, to manufacture the "Leaf". It seems like a good vehicle, but, with a range of only 100 miles on a charge, although it would be perfect for commuting, it wouldn't be feasible for most people to have as their only vehicle, I suspect.

[Sweetpea]

Originally Posted by HarryT

Nissan are also building a plant in Sunderland, in the NE of England, to manufacture the "Leaf". It seems like a good vehicle, but, with a range of only 100 miles on a charge, although it would be perfect for commuting, it wouldn't be feasible for most people to have as their only vehicle, I suspect.

I'd buy it as a second car. I agree you'd need a petrol car for longer distances, until the batteries are improved and all stations have a speed loader....

[GeoffC]

An argument for the 100 mile range would be that for many journeys it would be sufficient.

Mind that would have to be an accurate 100 miles - more accurate than the so called mpg ranges given for cars at the moment. The last thing anyone would want is to do a return journey of 75 miles only to discover the hills and other road conditions drains the battery faster than expected.

[Sweetpea]

Originally Posted by GeoffC

An argument for the 100 mile range would be that for many journeys it would be sufficient.

Mind that would have to be an accurate 100 miles - more accurate than the so called mpg ranges given for cars at the moment. The last thing anyone would want is to do a return journey of 75 miles only to discover the hills and other road conditions drains the battery faster than expected.

Yes. The average commuter, who lives just too far to go by bike or not really in reach of public transport (aka, me...) would profit greatly by electric cars.

The final specs will probably say something like: range between 50km and 100km, depending on road conditions and gradients in the terrain. Which would mean I'd get the max out of it...

[Steven Lyle Jordan]

Originally Posted by HarryT

Nissan are also building a plant in Sunderland, in the NE of England, to manufacture the "Leaf". It seems like a good vehicle, but, with a range of only 100 miles on a charge, although it would be perfect for commuting, it wouldn't be feasible for most people to have as their only vehicle, I suspect.

It could still be a primary, or even an only vehicle, if your daily range is low enough, if you can plan a bit in advance and combine trips, and if you have access to a secondary vehicle source, such as a rental service or public trans. Most Americans could do it, if they wanted to (it's just so alien to them that they'd never consider it.

I'd do it in a heartbeat. As I've said, the Leaf will be my next ride, unless something better is offered when I'm ready to buy.

[Steven Lyle Jordan]

Originally Posted by HarryT

Nissan are also building a plant in Sunderland, in the NE of England, to manufacture the "Leaf". It seems like a good vehicle, but, with a range of only 100 miles on a charge, although it would be perfect for commuting, it wouldn't be feasible for most people to have as their only vehicle, I suspect.

It could still be a primary, or even an only vehicle, if your daily range is low enough, if you can plan a bit in advance and combine trips, and if you have access to a secondary vehicle source, such as a rental service or public trans. Most Americans could do it, if they wanted to (it's just so alien to them that they'd never consider it.)

I'd do it in a heartbeat. As I've said, the Leaf will be my next ride, unless something better is offered when I'm ready to buy.

[Sweetpea]

Originally Posted by Steve Jordan

It could still be a primary, or even an only vehicle, if your daily range is low enough, if you can plan a bit in advance and combine trips, and if you have access to a secondary vehicle source, such as a rental service or public trans. Most Americans could do it, if they wanted to (it's just so alien to them that they'd never consider it.)

I'd do it in a heartbeat. As I've said, the Leaf will be my next ride, unless something better is offered when I'm ready to buy.

You think it's so important that you repeat yourself?

No idea how rental is organized... But yes, it depends on the services around you, whether a small-range car is fitting or not.