Electric Vehicles

[TurkeysGhost]

It's been mentioned upthread and I think the consensus was that it's a non-starter.

A battery small enough to carry to and from a vehicle and into a residence is unlikely to have enough capacity to make a significant difference.

The likely solution would be to have charging points everywhere, where you work, where you shop, where you eat, in the streets and possibly even allowing people to use domestic chargers. If I'm not using my charger outside my house, then why not allow someone to pay to use it to charge their car ?

Countries like Norway will act as a laboratory for the feasibility for this kind of thing. Norway is pretty good too because it has some urban centres but also a very sparsely populated hinterland.

I wonder if swappable batteries would work for fleet vehicles. Most of these bus and taxi services already have depots with decent mechanic services and gas stations. Electrifying these vehicles is tough because they are in continuous use, so there's never a good time to take them out of service to charge for hours.

Even if the battery were several hundred pounds, a bus depot should have no problem swapping them out quickly with the proper tools.

 

[jadebox]

Some electric trucks (and cars) have small generators on board so that they can be recharged using gas while driving. This differs from hybrids where a gas engine can directly power the wheels. I read about delivery trucks using this technology in England so that they can drive to London using the generator to extend the electric range then go fully electric when in the city.

There are roads with induction chargers built in so that vehicles can be charged while they are driving. That would seem to make sense for buses. You can buy a charger like that for your driveway, but they are expensive (at least for now).

 

[Steve]

This assumes that the price of fuel remains stable. If it were to be 10 times higher (or even 3-4 times higher as it is in parts of Europe) then the economic argument changes somewhat.
It's almost certain that our next purchase will be an EV. When that will be depends on how long Mrs Don's 12 year old Skoda keeps on going. If past experience is anything to go by, it could be a considerable time.

For most people yes. For myself the only decision would be continue to drive or stop driving. I do not foresee ever having the cash to buy a car, and with my fixed income a loan would not be approved even if I could make the payments. As I say, it is my current car or no car.

The EV discussion is purely academic for me. But not for my daughter whose next vehicle purchase will undoubtedly be electric. When she becomes the main source of transportation for her decrepit parents we will travel by EV as our default.

 

[ponderingturtle]

I wonder if swappable batteries would work for fleet vehicles. Most of these bus and taxi services already have depots with decent mechanic services and gas stations. Electrifying these vehicles is tough because they are in continuous use, so there's never a good time to take them out of service to charge for hours.

Even if the battery were several hundred pounds, a bus depot should have no problem swapping them out quickly with the proper tools.

It could certainly be designed to be pretty easy to swap, and for fleet vehicles it might make sense. Though how it compares to say fast charging while the driver has lunch I don't know.

It really only seems practical for a fleet of high mileage local vehicles. They need to put enough miles on them between breaks for the driver end of day usage to make putting a larger battery in them impractical but need to be able to stop by the swap station and not be 100 miles away from it.

 

[Steve]

Some electric trucks (and cars) have small generators on board so that they can be recharged using gas while driving. This differs from hybrids where a gas engine can directly power the wheels. I read about delivery trucks using this technology in England so that they can drive to London using the generator to extend the electric range then go fully electric when in the city.

There are roads with induction chargers built in so that vehicles can be charged while they are driving. That would seem to make sense for buses. You can buy a charger like that for your driveway, but they are expensive (at least for now).

That would be like a big, big improvement on overhead trolley wires that has the advantage of being used by all vehicles,

 

[Fast Eddie B]

Some electric trucks (and cars) have small generators on board so that they can be recharged using gas while driving. This differs from hybrids where a gas engine can directly power the wheels.

As an aside, in our Clarity even with the battery depleted, most driving is done with the electric motor powering the front wheels while the 1.5 liter gas engine provides the electricity to do so. One thing you have to get used to is the engine speed is largely divorced from road speed, which seems odd at first - the engine speeding up while the car doesn’t feels a lot like a clutch slipping.

I said “most driving” because at speeds between 45 and 70 mph and under certain loads the engine can decide to drive the front wheels directly. It’s the “Engine Drive Mode” in the diagram below.

Honda apparently found a way to do so to increase efficiency at those speeds. The whole system is rather complex, but in actual use is pretty seamless.

 

[KDLarsen]

I wonder if swappable batteries would work for fleet vehicles. Most of these bus and taxi services already have depots with decent mechanic services and gas stations. Electrifying these vehicles is tough because they are in continuous use, so there's never a good time to take them out of service to charge for hours.

Even if the battery were several hundred pounds, a bus depot should have no problem swapping them out quickly with the proper tools.

For city/transit busses, it might not even be necessary.

Looking at the future route network for our busses, the longest run will be something in the area of 25 km/16 miles, and going with the above mentioned "safe" range of around 200 km/125 miles (as opposed to the published range of 320 km/200 miles on a full charge) you should be able to get 8 roundtrips in before a recharge became necessary. That's at least 16 hours of running time, not including breaks at the terminus, a timeframe I don't think any of our current fleet is even approaching.

 

[JoeMorgue]

How realistic is swappable batteries?

Not very. Outside of engineering and practical considerations a battery pack is is key, integral piece of an electric car. You don't want to risk getting a crappy/lemon battery everytime you "fill the tank" on your electric car.

The other big thing with electrical cars is that every viable business model for them on the table right now is yet another "service as product" where you will never truly fully your own your car.

 

[Monza]

Some electric trucks (and cars) have small generators on board so that they can be recharged using gas while driving. This differs from hybrids where a gas engine can directly power the wheels. I read about delivery trucks using this technology in England so that they can drive to London using the generator to extend the electric range then go fully electric when in the city.

The Chevy Volt operates this way. It's very interesting technology. It's an electric vehicle, but once the battery reaches a minimum charge threshold, the IC engine kicks-on and turns a generator to charge the battery.

 

[MRC_Hans]

Agreed. I have learned a lot from this discussion and I now know that the charging issue is not nearly as bad as I thought. It is, however, still considerably more time consuming that simply filling up at a gas station. On a longer trip stops would have to be planned ahead.

Again. I am not using this as a way to criticize EV's. The infrastructure will continue to improve, battery range will continue to improve, and the price of electric cars will hopefully continue to drop to a range where they are affordable for many more people. If I were younger and wealthier I would definitely see an EV in my future. As it is my current gas guzzler could well last me the rest of my driving life and $50 a month for gas is manageable even on my income.

Well, will not likely happen in the life-span on a car you already have, but at some point, gasoline prices will start to go up. At first, as demand is falling, they could actually fall, although I suspect producers may try to increase profits instead. But then production will start to become unprofitable (already happening for tar sand and shale), and the supply will go down.

There is also the probability that some governments will increase taxes on fossil fuels, to finance and drive the change to sustainable energy.

At that point old gas cars will become collectors objects and museum pieces.

Hans

 

[ponderingturtle]

Not very. Outside of engineering and practical considerations a battery pack is is key, integral piece of an electric car. You don't want to risk getting a crappy/lemon battery everytime you "fill the tank" on your electric car.

I wonder if such systems are used in mobile robots expected to have 24hr service. That is the kind of usage that would seem to make the most sense. For personal transport not so much.

 

[JoeMorgue]

The Chevy Volt operates this way. It's very interesting technology. It's an electric vehicle, but once the battery reaches a minimum charge threshold, the IC engine kicks-on and turns a generator to charge the battery.

Just to keep the technology terminology clear.

In general.

- Electric Car. Is driven completely by an electric motor. Tesla's, the Chevy Bolt, etc, fall into this category.
- Hybrid. Has a gasoline engine same as a traditional car, but also has electric motors and batteries. When the car brakes the braking power is used to charge the batteries and that power is used to give the car extra power while driving, reducing the need for the combustion engine. The Prius and Insight fall into this category.
- Plug In Hybrid. Same as a hybrid, but you can also charge the batteries directly.
- Range Extended Car. Fully electric, but has a generator/engine that can charge the battery after it has depleted or power the vehicle directly.

 

[MRC_Hans]

I wonder if swappable batteries would work for fleet vehicles. Most of these bus and taxi services already have depots with decent mechanic services and gas stations. Electrifying these vehicles is tough because they are in continuous use, so there's never a good time to take them out of service to charge for hours.

Even if the battery were several hundred pounds, a bus depot should have no problem swapping them out quickly with the proper tools.

Thing about public transport is that it tends to have very varied loads over a day. So there will be plenty of opportunity to charge vehicles during the low periods.

However, I think we are here having some tunnel-vision again, in reality some future scenario could be this:

There is already a move (at least in Europe) towards cars that are not owned. You rent them when you need them. There is also the quest for fully automatic cars. Let's assume those are combined (and assume various safety challenges are solved), then a car would be something you ordered on your smartphone (or whatever communication terminal we may have in a decade or two). You will tell the app where you want to go, and an automatic car will appear at the curb. You will get in, take a nap or read a book, and leave it at the destination. You will be billed online. If you order a longer ride than the range of the usual car, you will either get a long-range version, or you will be requested to change car during the trip. If you are a larger group, you order a larger car.

Mind you, this scenario needs not be applied universally. In some areas, it may never be feasible, in others it could be implemented tomorrow (well, within a few years ).

Hans

 

[MRC_Hans]

I wonder if such systems are used in mobile robots expected to have 24hr service. That is the kind of usage that would seem to make the most sense. For personal transport not so much.

Well, according to figures given in this thread, it seems the current EVs have about 5:1 operation to charge ratio, perhaps even better in an optimized set-up. So instead of battery swapping, which in an automated setting would require it's own class of robotics, you could simply have 20% extra robots. They could then just seek the charging station when needed. Commercial robots like vacuum cleaners and lawn movers already do this.

Hans

 

[Disbelief]

How realistic is swappable batteries?

Especially for fleet vehicles like buses or taxis, seems like having a depot with charged batteries ready to swap in seems like a good solution.

Hell, seems like a good solution for personal vehicles too. I may not have power at my parking spot, but every residence has power inside. I could see having a spare battery charging under a desk as a good solution for those that can't charge in place wherever the car is parked.

It's not, the manufacturers are not going to allow that many people to touch the vehicles and swap the battery. To comply with safety and crash requirements, the secure would be important along with the reattaching the cables correctly. Manufacturers would not want to take on that potential liability.

I have a bit of a different perspective, I work in the plant that builds the Chevy Bolt.

 

[Steve]

Well, will not likely happen in the life-span on a car you already have, but at some point, gasoline prices will start to go up. At first, as demand is falling, they could actually fall, although I suspect producers may try to increase profits instead. But then production will start to become unprofitable (already happening for tar sand and shale), and the supply will go down.

There is also the probability that some governments will increase taxes on fossil fuels, to finance and drive the change to sustainable energy.

At that point old gas cars will become collectors objects and museum pieces.

Hans

I agree on all points.

 

[bruto]

The Chevy Volt operates this way. It's very interesting technology. It's an electric vehicle, but once the battery reaches a minimum charge threshold, the IC engine kicks-on and turns a generator to charge the battery.

It sounds a bit like an in parvo diesel electric locomotive, except with an intermediate battery pack.

It seems like a pretty good idea, since a fairly small IC motor can achieve more efficiency if it's run at a constant speed, and it provide that little bit of safety net for people worried about the more drastic effects of short range. And whenever the range is not exceeded, the motor just sits there harmlessly.

 

[Fast Eddie B]

It's not, the manufacturers are not going to allow that many people to touch the vehicles and swap the battery. To comply with safety and crash requirements, the secure would be important along with the reattaching the cables correctly. Manufacturers would not want to take on that potential liability.

I envision battery modules that simply slide or drop in, not requiring cabling. Something like the rechargeable batteries on power tools. “Swap Stations” would probably need to verify the serviceability of batteries that are swapped.

I have a bit of a different perspective, I work in the plant that builds the Chevy Bolt.

Cool!

 

[ponderingturtle]

I envision battery modules that simply slide or drop in, not requiring cabling. Something like the rechargeable batteries on power tools. “Swap Stations” would probably need to verify the serviceability of batteries that are swapped.

But who owns them? Who buys them and pays for their replacement when they lose capacity?

With how battery tech has progressed it really looks like these are more quaint old fashioned ideas for how cars are actually used.

 

[Fast Eddie B]

But who owns them? Who buys them and pays for their replacement when they lose capacity?

The devil, as always, is in the details.

Still, none of that seems insurmountable. It seems roughly analogous to what happens when you exchange an empty propane tank for a full one. In that case you “own” the one given to you for the time you have it, and the dealer verifies your exchange tank is still legally in limits.

It’s also been pointed out that even after a car’s battery pack drops below a certain arbitrary threshold, it could still have value as part of a “PowerWall” or other backup usage. I have no doubt a successful business model could be dreamed up once the demand is there.