Self-charging electric cars

[Ara Pacis]

Technically, zinc-air, aluminum-air, and lithium-air devices are fuel cells, yes. However, they are practically identical to "batteries" in use, and essentially nothing like hydrogen or hydrocarbon fuel cells. No exotic catalysts, no plumbing, no requirement for high temperatures...

Would it make a difference in definition if the reactants were used up in a way that made the battery unusable versus a device that could be reloaded with one or more reactants to continue the reaction?

[cjameshuff]

Would it make a difference in definition if the reactants were used up in a way that made the battery unusable versus a device that could be reloaded with one or more reactants to continue the reaction?

Not really...metal-air fuel cells are often single-use. Without super-expensive catalysts or complex plumbing with pumps and valves, there's not as much pressure to make them refuelable.

[NEOWatcher]

However, max load can be 20kWh, and if it stayed there the fuel cell would expend it's fuel in about 20 hours.

Make up any hypothetical worst case scenario you want. I'm not going to talk about unrealistic situations.

On the other hand, if it was powering the grid at a load equivalent to 60mph (~100kWh), it might run empty in 4 hours. (Feel free to check my math.)

And your Leaf (24KWh) would be dead in 15 minutes.

Yes, but that's no different than driving a car with less than a full tank of gas, which most people do. Go out to your car now and tell us how full it is. We'll wait.

Not when you are considering the range.
When I have a 10% amount of gas, I still have 45 to 60 miles to get to a gas station.
If I have 10% charge, then that goes down to 6 to 12 to get to a charge station.

although a 240VAC dedicated car charger station would be better and allow you to charge up to 30 miles of driving capacity in 5 minutes.

Where do you get that figure?
The Leaf takes 8 hours at 240v to recharge. Let's say an average 100 miles per charge, 5 minutes will get you about one mile.

[NEOWatcher]

120VAC power plugs are more prolific than gas stations

But; are they publicly accessible? I seriously doubt it.

[Ara Pacis]

Make up any hypothetical worst case scenario you want. I'm not going to talk about unrealistic situations.

Not hypothetical, just a statement of fact based on what's allowable for 120v, according to the source.

And your Leaf (24KWh) would be dead in 15 minutes.

With better battery tech...

Not when you are considering the range.
When I have a 10% amount of gas, I still have 45 to 60 miles to get to a gas station.
If I have 10% charge, then that goes down to 6 to 12 to get to a charge station.

What are you driving? Most ICE seem to mate tanks to cars so that they get maybe 400 miles before refueling. More efficient cars tend to get smaller tanks.

Where do you get that figure?
The Leaf takes 8 hours at 240v to recharge. Let's say an average 100 miles per charge, 5 minutes will get you about one mile.

http://elecauto.org/how-long-to-rech...e-nissan-leaf/
After looking at the Nissan site, I see that the Commercial Charger is 480VDC.

There's also a mention of 5 minute charging here: http://green.autoblog.com/2011/11/17...-game-changer/

Based around the CHAdeMO protocol and operating on 480 volts, Nissan's new station can not only fill an empty battery in a hurry, it could potentially charge a Leaf from half empty to nearly full in the same five minutes it takes most cars to add a few gallons of gas.

Something similar from Edmunds: http://www.autoobserver.com/2011/11/...d-charger.html

Nissan North America said today that it will begin U.S. sales of a newly developed electric vehicle rapid-charge station that costs about a third of what other rapid charges are selling for. Although the sales program was just announced, Nissan already has taken orders for “many” of the chargers, Nissan Leaf sales and marketing director Brendan Flynn told AutoObsever. The $9,900 Nissan device is a 480-volt direct-current (DC) system that can bring an empty 24-kilowatt-hour lithium-ion battery pack up to an 80 percent charge in about 20 minutes.

And from a Cars.com experiment: http://blogs.cars.com/kickingtires/2...g-two-evs.html

Our Leaf's battery-level meter started with one bar out of 12, or just over 8%, with a predicted range of 12 miles. The range increased by two to three miles for each minute of charging. For comparison, we're happy to see our Leaf add 10 miles of range for every hour of charging at Level 2.

As the minutes passed, the charging slowed. By the 10-minute mark, it was adding two miles of range every minute instead of three.

That's around 30 miles in 10 minutes. They were charging it at suboptimal temperature, so perhaps it would have charged even faster.

But; are they publicly accessible? I seriously doubt it.

You might have to ask. What, you don't like begging for handouts?

[cjameshuff]

These fast-charging systems require another battery pack of larger capacity and higher voltage than the one in the vehicle, add charging losses, and I never see the impact on battery life mentioned. I don't see any reason to prefer them over battery swapping.

[NEOWatcher]

Not hypothetical, just a statement of fact based on what's allowable for 120v, according to the source.

There's "available" and there's "common usage". I'm trying to stick to the 80/20 rule (basically, how do we cover most conditions.

With better battery tech...

That's assuming we can get better tech. I don't have a doubt we will, but how much, how soon and at what price is speculation, and I'm trying to stick with what we know now.

What are you driving? Most ICE seem to mate tanks to cars so that they get maybe 400 miles before refueling. More efficient cars tend to get smaller tanks.

My car is rated at 38mpg highway with a 15 gallon tank, I get 40 highway. I get 30 mpg normal (virtually no highway) driving. The math fits.

That's around 30 miles in 10 minutes. They were charging it at suboptimal temperature, so perhaps it would have charged even faster.

Way off of what you said.
And how often would the general user be at optimal conditions? I would think a suboptimal temperature would be a better gauge of real life conditions.

You might have to ask. What, you don't like begging for handouts?

NO; and frankly, that would be an insult to put someone in that position because "YOU" think it's an acceptable alternative for retail outlets.

[Ara Pacis]

There's "available" and there's "common usage". I'm trying to stick to the 80/20 rule (basically, how do we cover most conditions.

Which is why it's good to know extrema.

That's assuming we can get better tech. I don't have a doubt we will, but how much, how soon and at what price is speculation, and I'm trying to stick with what we know now.

Or just larger batteries with current tech.

My car is rated at 38mpg highway with a 15 gallon tank, I get 40 highway. I get 30 mpg normal (virtually no highway) driving. The math fits.

What car is that?

Way off of what you said.

How so? I was quoting an article that no one has yet refuted. 10 minutes is a lot closer to 5 minutes than it is to 480 minutes.

And how often would the general user be at optimal conditions? I would think a suboptimal temperature would be a better gauge of real life conditions.

In Chicago, where the test occurred, I'd say about half the year but with the recent warmth, more like 3/4 of the year.

NO; and frankly, that would be an insult to put someone in that position because "YOU" think it's an acceptable alternative for retail outlets.

Don't you have any sense of humor?

[NEOWatcher]

Which is why it's good to know extrema.

Yes; no problem in knowing it, but we are talking about normal everyday conditions to cover most people.

What car is that?

Cruze LT. 15.6 gallon.

How so? I was quoting an article that no one has yet refuted. 10 minutes is a lot closer to 5 minutes than it is to 480 minutes.

Another example of you mis-quoting, mis-interpreting or some other situation.
Where did I say 480 minutes for a partial charge(which is what I was comparing to for 240v). I cited the data for the Leaf and showed you exact numbers of what you would get. Where am I wrong?

Besides, you did not quote the article, you mixed up the article and quoted the 480v statement.

Don't you have any sense of humor?

I do, but sans emoticon it's hard to tell.

Do you have a real reply to your statement about the lack of public outlets?

[starcanuck64]

I think this was discussed here earlier, it does look like wireless charging of electric vehicles is being developed.

http://www.egovmonitor.com/node/52940

Microchip developer Qualcomm is testing a new wireless electric-vehicle charging technology in London.

Qualcomm says plug-in charging is too "cumbersome," its new technology could lead to electric cars being charged whilst driving.

The trials will take place before the end of the year, with an adapted version of Formula 1 car designer Delta Motorsport's E4 coupe electric car being the main test vehicle. Further tests will be carried out in 2013 using Renault electric cars.

[Ara Pacis]

Another example of you mis-quoting, mis-interpreting or some other situation.
Where did I say 480 minutes for a partial charge(which is what I was comparing to for 240v). I cited the data for the Leaf and showed you exact numbers of what you would get. Where am I wrong?

In response to my statement about a 30 mile-worth charge in 5 minutes you said it would take 8 hours (480 minutes) to fully charge, which is your preference as stated several times. I figured if you wanted to make a comparison of 30-mile-worth of charge at 5 minutes per mile, I'd let you make it (150 minutes, or 2.5 hours, btw). Even at 150 minutes for 30 miles-worth of charge, the 10 minute charge is closer to the quoted 5 minute charge.

Besides, you did not quote the article, you mixed up the article and quoted the 480v statement.

I didn't mix up anything. The first link I posted above (this one) as my source didn't say it was a 480v system. All it said was this:

The Nissan Leaf will offer 4 different charging options.

110 volt “opportunity” charger. For use when no other charging option is available. A full charge will take about 16 hours using this method
220 home charger. This is an at-home installed charger that is meant to be your daily charging solution. Total charge time is about 8 hours using this charger.
Commercial Fast Charge. This will give an 80% charge in just about 30 minutes.
The Commercial Fast Charge can also be set to give an extra 30 miles with a super quick 5 minute charge.

, which looks like it meant a 240v charger, until I looked it up when you suggested it was in error.

Do you have a real reply to your statement about the lack of public outlets?

Well, it can work on 120VAC, so any gas station has the infrastructure available if they wanted to use it as another line of business. Same for homeowners or shop-owners or restaurant owners in strategic locations. And in the event of a emergency, one can beg for a plug in. More likely, I think, may be that tow-trucks and interstate assistance vehicles may carry generators or battery packs for recharging stranded vehicles, to give them enough juice to make it to a known commercial charging station or a fuller charge with a payment on site.

[NEOWatcher]

In response to my statement about a 30 mile-worth charge in 5 minutes you said it would take 8 hours (480 minutes) to fully charge

Yes, but that was only to set up the data for my result, I did not stop there.

which is your preference as stated several times.

Preference? I don't know why you think I favor an 8 hour charge?
I'm just using it for known numbers on a common system to base my further calculations. Fact, not preference.

I figured if you wanted to make a comparison of 30-mile-worth of charge at 5 minutes per mile, I'd let you make it (150 minutes, or 2.5 hours, btw).

Exactly, I just stated in in miles for a 5 minute charge (one mile) so to get the 30, it's my 1 mile times 30 = 150 minutes. It seems like there is no difference in opinion there.

Even at 150 minutes for 30 miles-worth of charge, the 10 minute charge is closer to the quoted 5 minute charge.

The 10 minute charge is at a different voltage. I was trying to keep apples to apples comparison.
Yes; it would be great if I reached a 480V charger, and I could probably live with that if I were driving just out of range and needed to get to a place where I would have the car sit and recharge.
No difference of opinion there.
I'm trying to keep this on what my opinon on what common availabilty would be since most places already have 240v service. I can't speculate on how fast service stations would upgrade thier service for the occasional "oops, I need a little more before I get to where I'm going".

I didn't mix up anything. The first link I posted above (this one) as my source didn't say it was a 480v system.

Ok; not a mix up, but based on an assumption. I did base my comparison on your 240v statement.
My assumption was that I couldn't take the leap that a commercial charger could be 10 times faster than a home charger using the same voltage. So; I ruled that option out as not having enough information. The 240v still matches my numbers.

Well, it can work on 120VAC, so any gas station has the infrastructure available if they wanted to use it as another line of business. Same for homeowners or shop-owners or restaurant owners in strategic locations. And in the event of a emergency, one can beg for a plug in.

Yes; that is a viable option. I think it's going to take time for that to be available. It's probably going to be at a premium price so they can make some money on it, but it would keep you from being stranded.

I've seen a few (extremely few) public charging stations around, but I never took a look at what they are "charging" for it. (The ones I see most often, they seem not to care who parks in those spots though, so they are often unavailable)

(As a side note related to premium price, many campgrounds I go to charge an extra couple of bucks per day if your unit has air conditioning wether you use it or not and in any weather. Over the long run, they make quite a bit of money on that since you would need to run the air for nearly 24 hours to use that much.)

Looking at power requirements, the 240v charger pulls about 30 amps. Not too bad that a few outlets could probably be absorbed by a business. But; for wide scale use and availabilty, they'd have to be serious about offering it with high availability and upgrade thier service.

More likely, I think, may be that tow-trucks and interstate assistance vehicles may carry generators or battery packs for recharging stranded vehicles, to give them enough juice to make it to a known commercial charging station or a fuller charge with a payment on site.

I would think that a battery pack would have a slower recharge rate than the other "live" hookups.
Therefore, it might be faster for them (cheaper) to just tow you to a charge station than to wait around for the charge. Then, they would need several chargers for a day's work and run into the possiblity of needing to tow you anyway if they run out.
Although, that's going to depend on how densly populated (available outlets) the area is. In the city, you might only need that mile or so, but in the more rural area you will need that several miles.

[danscope]

Makes the case for the hybrid, doesn't it? Let the pony engine run while you are in the parking lot to ramp up your charge, and drive home later. Untill we see really extended performance from the next generation of batteries, I think we are looking at such a scheme for extended range. A dead car on the highway is a death trap. No question .

[Ara Pacis]

Yes, but that was only to set up the data for my result, I did not stop there.

Preference? I don't know why you think I favor an 8 hour charge?
I'm just using it for known numbers on a common system to base my further calculations. Fact, not preference.

I was referring to the state of charge, not the timeframe. But looking back I see that was according to statements made by cjameshuff, not you. You responded to a response I made to him in that context, so I carried it over without considering it was a different person.

The 10 minute charge is at a different voltage. I was trying to keep apples to apples comparison.

Yeah, but neither of us knew that at the time.

Yes; it would be great if I reached a 480V charger, and I could probably live with that if I were driving just out of range and needed to get to a place where I would have the car sit and recharge.
No difference of opinion there.
I'm trying to keep this on what my opinon on what common availabilty would be since most places already have 240v service. I can't speculate on how fast service stations would upgrade thier service for the occasional "oops, I need a little more before I get to where I'm going".

Well, the Nissan charger I mentioned above is not only a breakthrough in fast charge time but in price -- it's being sold for around $10,000, which is 1/4 the price for the previous models.

Ok; not a mix up, but based on an assumption. I did base my comparison on your 240v statement.
My assumption was that I couldn't take the leap that a commercial charger could be 10 times faster than a home charger using the same voltage. So; I ruled that option out as not having enough information. The 240v still matches my numbers.

Right.

I've seen a few (extremely few) public charging stations around, but I never took a look at what they are "charging" for it. (The ones I see most often, they seem not to care who parks in those spots though, so they are often unavailable)

According to the last article I linked above about the charge experiment, the "CharJit" system costs $7 for a session, which is supposed to get you to an 80% state-of-charge (using the new 480v rapid charge system, AKA Level 3, AKA CHAdeMO). I don't know how much it would cost for a 240v session (Level 2), although the authors state they had gotten that for free (billing system not in place). According to the article the Chicago area only had 3 confirmed Level 3 charging stations, but the city has plans to install 70 more (and 207 Level 2 charging stations as well).

Looking at power requirements, the 240v charger pulls about 30 amps. Not too bad that a few outlets could probably be absorbed by a business. But; for wide scale use and availabilty, they'd have to be serious about offering it with high availability and upgrade thier service.

I would think that a battery pack would have a slower recharge rate than the other "live" hookups.
Therefore, it might be faster for them (cheaper) to just tow you to a charge station than to wait around for the charge. Then, they would need several chargers for a day's work and run into the possiblity of needing to tow you anyway if they run out.
Although, that's going to depend on how densly populated (available outlets) the area is. In the city, you might only need that mile or so, but in the more rural area you will need that several miles.

Actually, one company has already developed a mobile 50kWh CHAdeMO charging unit (80% charge in 25 minutes). Alternately, a service/tow truck could use flywheels or ultracapacitors or even a fuel cell to charge the car battery rapidly. Perhaps gas stations would use one or more flywheels to slowly store energy at a lower load to be ready to charge a car rapidly when necessary.

[Ara Pacis]

Makes the case for the hybrid, doesn't it? Let the pony engine run while you are in the parking lot to ramp up your charge, and drive home later. Untill we see really extended performance from the next generation of batteries, I think we are looking at such a scheme for extended range. A dead car on the highway is a death trap. No question .

Only if the battery capacity is less than your commute.

And why would a "dead car" = "death trap"?

[NEOWatcher]

Well, the Nissan charger I mentioned above is not only a breakthrough in fast charge time but in price -- it's being sold for around $10,000, which is 1/4 the price for the previous models.

That's for a single car right?
Doesn't that require a power service upgrade (to 480v)? That's an additional cost too.

They'd have to project a high usage to make it profitable to have it.

[Ara Pacis]

That's for a single car right?
Doesn't that require a power service upgrade (to 480v)? That's an additional cost too.

They'd have to project a high usage to make it profitable to have it.

What do you mean by single car? At a public station it can be used by one at a time, but a session is only about 20 minutes to half an hour. The 480VDC CHAdeMO design is a suggested standard that is being used by more than on EV manufacturer. In the article, they charge both a Nissan and a Mitsubishi, but both EVs needed to have a CHAdeMO connector.

Also, a full charge at $7 leaves a lot of profit per session due to the currently low cost of electrical power. But traffic volume would be nice. Of course, volume might drive the price down via amortization of investment, economies of scale in manufacturing and competition, however grid load and electrical rates might drive costs up, reducing profit margin.

[cjameshuff]

What do you mean by single car? At a public station it can be used by one at a time, but a session is only about 20 minutes to half an hour. The 480VDC CHAdeMO design is a suggested standard that is being used by more than on EV manufacturer. In the article, they charge both a Nissan and a Mitsubishi, but both EVs needed to have a CHAdeMO connector.

A Leaf might only take 20 minutes, but the Leaf only has a 24 kWh battery pack. Battery packs with more capacity will take longer. And it charges at up to 62.5 kW, more than your typical US household's total service capacity...running one of these straight off the grid will require special grid connections to handle the high peak current. Running a parking lot full of chargers straight off the grid will make for an unhappy power company.

Rather than require the homeowner to buy special high-capacity service just to charge their car, concepts for home fast-chargers I've seen charge from a stationary battery pack, which must have at least as much capacity as the one in the vehicle, and which itself needs to be charged afterward. Public charging stations would probably take a similar approach to reduce energy costs, using a large stationary array of batteries for load leveling. Again, swapping batteries seems a fundamentally much better approach...less wear and tear on the batteries, lower, more constant and more predictable load on the power grid, and it can be done in minutes, not hours.

[starcanuck64]

High-end electric cars like the Tesla Model S come with superchargers that will provide a half charge for a 85 kWh battery in 30 mins at 240V, many of those charging would create a major drain on the grid.

List of electric cars:

http://en.wikipedia.org/wiki/List_of...ctric_vehicles

[Ara Pacis]

A Leaf might only take 20 minutes, but the Leaf only has a 24 kWh battery pack. Battery packs with more capacity will take longer. And it charges at up to 62.5 kW, more than your typical US household's total service capacity...running one of these straight off the grid will require special grid connections to handle the high peak current. Running a parking lot full of chargers straight off the grid will make for an unhappy power company.

Yep. I see you've read the posts between NEOWatcher and me, and perhaps the articles I've linked as well. Why would the power company be upset at having paying customers?

Rather than require the homeowner to buy special high-capacity service just to charge their car, concepts for home fast-chargers I've seen charge from a stationary battery pack, which must have at least as much capacity as the one in the vehicle, and which itself needs to be charged afterward. Public charging stations would probably take a similar approach to reduce energy costs, using a large stationary array of batteries for load leveling. Again, swapping batteries seems a fundamentally much better approach...less wear and tear on the batteries, lower, more constant and more predictable load on the power grid, and it can be done in minutes, not hours.

I just mentioned the part about low-load energy storage with fast discharge at gas station a few posts ago. I don't know if the power companies would install a 480v three-phase service to a residence, but most residences need a 240v system. (they can use a 120 system, but it's slow and Nissan was cancelling orders for people who couldn't prove they were installing a 240v EVSE.) The home chargers uses an AC system and the car has a the actual charger/rectifier built-in to convert it to DC for the battery. A lot of homes already have 240VAC so it's just a matter of tying into their existing panel for the EVSE.

Apparently Nissan is releasing (in Japan) a new charging station that charges the EV battery to 80% in only 4 hours. It also allows the EV's battery to power the house for up to 2 days (6kWh). It sells for about $6,000.

[djellison]

Why would the power company be upset at having paying customers?

Because their infrastructure is singularly unequipped to handle these loads.

During the summer months, the electricity grid of Southern California is already at absolute peak capacity. Large industrial areas are often asked to try and reduce their consumption a day at a time to avoid rolling brownouts.

[cjameshuff]

Yep. I see you've read the posts between NEOWatcher and me, and perhaps the articles I've linked as well. Why would the power company be upset at having paying customers?

Because of the disruption to their other paying customers. They make their money by maintaining and operating the power grid so they can sell energy, and a customer that causes problems for the grid (via poor power factor loads, abrupt addition/removal of excessively large loads, etc) isn't a profitable customer.

A quick-charge station would be worse than an aluminum plant, which at least operates more or less continuously and can vary its load to reduce its own usage during peak consumption periods...supporting such enormous loads will take adding a lot of specialized and expensive infrastructure, but they won't be buying nearly as much energy as similar industrial users. Charging 10 100 kWh cars in an hour will take over 1 MW of power. 24-hour average power consumption will be only a small fraction of that, easily only tens of kilowatts on a slow day, making for a lot of severely underutilized infrastructure that must be maintained and could be used to support more profitable customers.

Battery swap stations not only don't have this problem, they could work to augment the grid, providing a highly predictable base load that can be decreased or even switched around to provide power to the grid during peak load.

[NEOWatcher]

What do you mean by single car? At a public station it can be used by one at a time...

Yes; that's what I mean.

But traffic volume would be nice. Of course, volume might drive the price down via amortization of investment, economies of scale in manufacturing and competition, however grid load and electrical rates might drive costs up, reducing profit margin.

Yep; predicting that is the hard part.

[Ara Pacis]

Because of the disruption to their other paying customers. They make their money by maintaining and operating the power grid so they can sell energy, and a customer that causes problems for the grid (via poor power factor loads, abrupt addition/removal of excessively large loads, etc) isn't a profitable customer.

Profit is as profit makes. They'll just have to price it higher than it costs.

And it doesn't have to disrupt their other paying customers. It can be the impetus to create a different section of the grid that only stretches along interstates or to create grid-level energy storage for load leveling. It's an opportunity for Big Energy to be Big Energy and invest in something that makes good PR and for which they can claim to need to raise prices to cover the grand new order of blah blah blah. And that's in a "free market"; don't forget that it then gives the lobbyists that much more room to argue for government subsidies/tax breaks for their company/industry.

A quick-charge station would be worse than an aluminum plant, which at least operates more or less continuously and can vary its load to reduce its own usage during peak consumption periods...supporting such enormous loads will take adding a lot of specialized and expensive infrastructure, but they won't be buying nearly as much energy as similar industrial users. Charging 10 100 kWh cars in an hour will take over 1 MW of power. 24-hour average power consumption will be only a small fraction of that, easily only tens of kilowatts on a slow day, making for a lot of severely underutilized infrastructure that must be maintained and could be used to support more profitable customers.

Unless there is a buffering system for load-leveling at gas stations like I mentioned above. If chargers can pump a car to 80% in 30 minutes (or even faster according to some reports/claims) using chemical or other types of batteries stored on site, that might negate the need to swap them out. After all, it gives the customer time to shop and eat and spend more money.

Battery swap stations not only don't have this problem, they could work to augment the grid, providing a highly predictable base load that can be decreased or even switched around to provide power to the grid during peak load.

So can charging stations with energy storage on site, except they can do it better because they're not limited to one type of chemical battery for energy storage.

The problems with swapping batteries are thus:
physically moving batteries increases the risk for injury to the workers
physically moving batteries increases the risk for damage to the car
physically moving batteries increases the risk for damage to the batteries
physically moving batteries increases the risk for damage to the facility
physically moving batteries increases the risk for an installation flaw that appears later down the road and may cause harm to others at road speeds
disruption of load-leveling for physical removal
limitation on load-leveling to one or more specific types of chemical batteries used in vehicles
Limited to vehicle mobile chemical batteries
Limited to full charge swaps instead of partial charge
Not backwards compatible with non-battery-swappable cars
requires complicated ownership of batteries
requires complicated billing of batteries due to different states-of-charge at swap
requires complicated recording of battery history due to different types of charge and that introduces privacy concerns
requires industry wide standards or format wars and swap-here-not-there systems may emerge
requires industry to let less educated and experienced techs work on powerful chemical batteries putting the entire industry's reputation at stake
requires high power connection to grid, or more batteries than average on hand to satisfy peak swap rates or must turn customers away

By contrast, charging stations with energy storage have these additional advantages:
use more efficient batteries with different form factors
potentially use flywheel energy storage
potentially use hydrogen fuel cells or other types of fuel cells safely
potentially use hydrocarbon fueled generators of any sort of engine, size and efficiency level available
use less space by running wires to terminals instead of needing one or more enclosed service bays
Allows vehicles to park/shop/eat and wait for their terminal to activate instead of staying behind the wheel to creep forward in a queue for a swapping bay
Less employee labor needed overall, and labor needed can be less skilled and therefore costs less
use less space by running wires instead of needing accessible storage racks for batteries
can charge car batteries to different states-of-charge instead of requiring a full charge and full service event and duration
More adaptable to changes in battery chemistries and wiring architectures.

------

Yes; that's what I mean.

Ah, but there could be multiple charging stations at a gas station/truck stop/convenience center/interstate oasis. That might mean lots of power needed for each one... or each charger might be part of a smart queue so that chargers activate in an ordered sequence so that there's never an extremely high peak load to the convenience center. Chargers don't use the full power for the entire charging cycle as battery chemistry often slows down the charge towards the end of the charging cycle. (See the road-test quoted above about the quick charge starting at 3 miles per minute then slowing to 2 and then 1, etc.) So, a convenience center might have 10 chargers (all connected to a car) with only 5 active at one time and possibly at different loads. Meanwhile, people in those cars can get out and go inside and wait for a text from their car or a PA announcement that their car is ready without needing to let other people muck around inside it.

Addendum: That might sound expensive, to have that many charging stations, but with a smart queue system, each charging station could have the split downstream from the rectifier, with multiple connectors that activate in sequence. Thus, a convenience center could have only a few charging stations, each with four or more connectors to cars.

Yep; predicting that is the hard part.

Which is why it might be more advantageous to use a charging infrastructure, which is more adaptable, instead of a swapping infrastructure that has a stronger reliance on adherence to static and strict, dimensional standards.

[danscope]

Battery transfer is as simple as pulling out a log and replacing it. A lift picks up the car about ten inches (relieves the suspension )
and now the chassis stays stat, lines up with the system which extracts the battery, and installs the charged one . Every battery has it's own number. Computers keep track of batteries. The access hatch dovetails the electrical connection.

Best regards,
Dan

[Ara Pacis]

Battery transfer is as simple as pulling out a log and replacing it. A lift picks up the car about ten inches (relieves the suspension )
and now the chassis stays stat, lines up with the system which extracts the battery, and installs the freas one . Every battery has it's own number. Computers keep track of batteries. The access hatch dovetails the electrical connection.

Best regards,
Dan

One could describe open-heart surgery in roughly the same way.

[HenrikOlsen]

The part I see as likely to be the biggest obstacle to battery swapping is getting manufacturers to agree on a standard battery.

Making an automates swapping station is a problem eminently suited for engineers, the mechanical part of automating it is less complicated than a car wash.
That part of the problem is solvable.

[Ara Pacis]

The part I see as likely to be the biggest obstacle to battery swapping is getting manufacturers to agree on a standard battery.

I don't think that's as much an issue, as they will probably source their batteries from another party and they all use the same basic cells as it is. I don't think the manufacturers will resist automated swapping because of the battery itself but because of the necessary static design limitation.

Making an automates swapping station is a problem eminently suited for engineers, the mechanical part of automating it is less complicated than a car wash.
That part of the problem is solvable.

I don't think it's less complicated than a car wash. Car washes use loose floppy brushes, half of which spin on a vertical axis and the other half that spin on a horizontal axis and also move up and down. An automated battery system needs to use precision tools aligned with precision connectors applying precision torque or linear pressure to remove access panels that are designed to not only hold hundreds of kilograms of dense battery, but also hold that load under various accelerations during starts, stops and turns without opening accidentally or allowing in water. And manufacturers need to design this system in such a way that it's not so heavy as to compromise the car's performance or safety or aesthetics.

I'm sure that with enough compromises such a design criteria is solvable, but it doesn't seem worth it after reading about the fast new charging tech coming out and the hope of better battery or fuel cell chemistries.

[danscope]

Even if you discount the charged battery swap option , you still need to conveniently change out the battery for a better one ...
For many possible reasons. It simply makes good engineering sense to store it along the central axis in a protected case which
doubles as a central chassis and protects the device from many perils. And does so quickly with the least trouble. Plastic case in a plastic sleeved box beam. It goes in, it must come out . Thuds law of opposition. (from an obscure theater group .....
The Firesign theater .

[starcanuck64]

You can look at swappable batteries as a removable part of the vehicles structure, design them in such as way that they're easily removed but once in place add to the structural integrity of the vehicle.

You'd probably be using automated machinery to operate the switch-out so weight isn't going to be the central factor.