Self-charging electric cars

[Ara Pacis]

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.

the concern with weight isn't on the swap machinery, it's on the frame of the car or the battery holding hardware that needs to be able to hold the battery inside the car, even during maneuvers with high accelerations in different directions. You don't want a slide-in battery compartment door to open when the car stops suddenly. Worse yet, you don't want that to happen in collisions either, because the chances for a short circuit leading to thermal-runaway with vigorous venting may become higher if the battery is ripped from the vehicle through the weak point of an access panel.

[danscope]

The battery is an easily changed module. It isn't rocket science. And without the key, it won't be released. This is a
non - problem .

[JCoyote]

the concern with weight isn't on the swap machinery, it's on the frame of the car or the battery holding hardware that needs to be able to hold the battery inside the car, even during maneuvers with high accelerations in different directions. You don't want a slide-in battery compartment door to open when the car stops suddenly. Worse yet, you don't want that to happen in collisions either, because the chances for a short circuit leading to thermal-runaway with vigorous venting may become higher if the battery is ripped from the vehicle through the weak point of an access panel.

You are referencing problems in mechanical engineering that were solved over a century ago. These are not $12 gray market cd players we are talking about. Accessibility does not inherently weaken a compartment's design in the locked position. Your car's gas tank is unlikely to be held into your car in as solid a compartment as you seem to imagine you need for a battery electric. Nor is your car's battery. This isn't causing swarms of problems for you to complain about apparently.

Battery slides in on rail guides. Once in position large diameter pins slide in perpendicular to the rail guides on each side. Build the cover like a tank hatch if you really feel the need.

WHY is it that several people attack the idea of electric vehicles by demanding a higher build standard from them than what they already drive every day with gasoline?

And the thing about the battery is... there are numerous places in the vehicle one can be placed... the beauty of battery electric design is the flexibility of the "drive train". That would cause an issue in standards for handling equipment as a trade off for different installation. I endorse flat batteries along the belly though because it potentially allows the use of non-specialized tools with human muscle power to change if needed. Being able to change the battery with ramps and a pallet jack is a desirable feature. Do not argue about the weight of the battery please; I have personally moved thousands of pounds at once on pallet jacks with marginal effort.

[noncryptic]

Battery slides in on rail guides. Once in position large diameter pins slide in perpendicular to the rail guides on each side. Build the cover like a tank hatch if you really feel the need.

A demonstrated here.
Completed in a little over a minute, about the same amount of time or less as it takes to fill a car's fuel tank.

Better Place Battery Swap Demonstration
http://www.youtube.com/watch?v=qd0WPw3p2MQ

[Ara Pacis]

The battery is an easily changed module. It isn't rocket science. And without the key, it won't be released. This is a
non - problem .

Kinda like taking an engine out, eh?

[Ara Pacis]

You are referencing problems in mechanical engineering that were solved over a century ago. These are not $12 gray market cd players we are talking about. Accessibility does not inherently weaken a compartment's design in the locked position. Your car's gas tank is unlikely to be held into your car in as solid a compartment as you seem to imagine you need for a battery electric. Nor is your car's battery. This isn't causing swarms of problems for you to complain about apparently.

A gas tank also isn't likely to hold 110 gallons worth of mass. Did you see the episode of Mythbusters where they tried to get a gas tank to explode? It's not easy or common. Have you ever tried to short circuit a battery through a hard shock or penetration? It's a bit easier.

Battery slides in on rail guides. Once in position large diameter pins slide in perpendicular to the rail guides on each side. Build the cover like a tank hatch if you really feel the need.

Adding more mass.

WHY is it that several people attack the idea of electric vehicles by demanding a higher build standard from them than what they already drive every day with gasoline?

are you referring to EVs in general or swappable battery types? If this was an Fossil Fueled ICE or fuel cell with a swappable tank or engine, I'd make the same arguments.

And the thing about the battery is... there are numerous places in the vehicle one can be placed... the beauty of battery electric design is the flexibility of the "drive train". That would cause an issue in standards for handling equipment as a trade off for different installation. I endorse flat batteries along the belly though because it potentially allows the use of non-specialized tools with human muscle power to change if needed. Being able to change the battery with ramps and a pallet jack is a desirable feature. Do not argue about the weight of the battery please; I have personally moved thousands of pounds at once on pallet jacks with marginal effort.

And the thing about the battery is... there aren't numerous places in the vehicle one can be placed... the beauty of swappable design is the conformity it places on the automotive engineers.

The problem with weight is not about moving it with tools or robots. It's about the stress is makes on connecting hardware that must allow for easy and/or automated detachment and a sealable weather-housing, and it's about the mass of these additional components.

And I've used pallet jacks too, the manual types, and the double pallet length battery-driven types, and forklifts, and racklifts and cherry pickers and loaded and unloaded trucks and rail cars.

[Ara Pacis]

A demonstrated here.
Completed in a little over a minute, about the same amount of time or less as it takes to fill a car's fuel tank.

Better Place Battery Swap Demonstration
http://www.youtube.com/watch?v=qd0WPw3p2MQ

That seems a bit low. Will that have enough clearance to be legal in the US. It looks like a speedbump would damage the battery

[HenrikOlsen]

So regulate it 2 inches higher. That doesn't change anything about the design or the system in general, especially since that swapping station would be perfectly capable of handling such variations..

[neilzero]

3 or 4 years ago, The Tesla web site infered that that you could put 50 kWh in their battery in 6 minutes = 500 kW average. Possibly so, as their battery pack has a built in air conditioner to prevent cell over heating. Likely 500 kW would damage the connectors between car and charger. Worse the power company would charge plenty to run in power lines capable of suppling 1/2 megawatt a few hundred minutes per month = very low use of demand. Like most websites the amount of useful details is decreasing. Possibly they tried it and discovered that fast a charge reduced battery life expectancy even if the cells didn't get hot. It would destroy lead acid batteries in seconds. Some private homes have 50 kW available = 240 volts at 208 amps, but it is likely illegal to get the power directly from the main 300 amp circuit breaker. I suspect the Leaf and most competiters can be charged with 10 kWh with an appropriate charger in less than one hour, but have not seen any claims. Above 90% of full charge, I believe all batteries need to be charged slowly, but determining the 90% point is sometimes evassive. Also batteries are less tolerant of high charging rates, near the end of their useful life. Neil

[danscope]

Kinda like taking an engine out, eh?

Back in the day, you could pull a Volkswagen engine in 10 minutes. Fact.

[LotusExcelle]

The fastest I've ever pulled a complete engine is 35 minutes. But personal bests and anecdotes aren't relevant. I view the idea of swappable batteries as complex as Audi's R series race cars' swappable rear modules. It is NOT simple. In fact to apply that concept to consumer vehicles while require a VERY heavy investment from all parties, consumer included.

[danscope]

As I have explained, the battery is designed as a complete module, which slides into a box beam ( an extruded length of steel )
which also doubles as the car's chassis. You remove the endcap, disconect the cables ( 4 ....if you go with a design for an emergency
back up .....say 10% total energy ), slide out the module and slide in the charged unit.
I believe Ara P said " And the thing about the battery is... there aren't numerous places in the vehicle one can be placed " .
This plainly is not the case at all. Storing the battery on the centerline is the best place to have it , and have a balanced vehicle,
and a chassis strong enough to support it, and enclose the module in collision.
You simply have to want the vehicle.
Dan

[IsaacKuo]

A centerline box beam chassis reduces leg room and eliminates the middle seat, reducing a 5 person car to a 4 person car with less legroom.

[LotusExcelle]

As I have explained, the battery is designed as a complete module, which slides into a box beam ( an extruded length of steel )
which also doubles as the car's chassis. You remove the endcap, disconect the cables ( 4 ....if you go with a design for an emergency
back up .....say 10% total energy ), slide out the module and slide in the charged unit.
I believe Ara P said " And the thing about the battery is... there aren't numerous places in the vehicle one can be placed " .
This plainly is not the case at all. Storing the battery on the centerline is the best place to have it , and have a balanced vehicle,
and a chassis strong enough to support it, and enclose the module in collision.
You simply have to want the vehicle.
Dan

That simply isn't true. There are engineering compromises in every single aspect of every single vehicle and wanting a design is not the same as mass-producing a design. Car manufacturing (as Tesla has learned) is considerably more complicated than simply having the desire to make something.

[danscope]

An electric commuter car is not the same as an eight passenger vehicle. I would think large multi passenger vehicles would be hybrids employing an ICEngine to supplement the energy charge for such a demanding vehicle.

" If you look for all the compromises in any engineering solution..... you will surely find them . " John DeLorean or someone like him.

[Ara Pacis]

An electric commuter car is not the same as an eight passenger vehicle. I would think large multi passenger vehicles would be hybrids employing an ICEngine to supplement the energy charge for such a demanding vehicle.

" If you look for all the compromises in any engineering solution..... you will surely find them . " John DeLorean or someone like him.

A commuter vehicle might be too expensive for a single vehicle. A swappable vehicle paradigm might be better for that than a swappable battery paradigm. Although, I suspect a commuter distance might not need a battery swap.

[Ara Pacis]

So regulate it 2 inches higher. That doesn't change anything about the design or the system in general, especially since that swapping station would be perfectly capable of handling such variations..

Then it either takes up more room from the interior cabin, or it raises the vehicle, which can produce stability issues. In a small city without bumpy streets, it might work, but in the US with suburbs and exburbs, it may not be suitable as designed and may produce too many other problems if adapted.

[Ara Pacis]

3 or 4 years ago, The Tesla web site infered that that you could put 50 kWh in their battery in 6 minutes = 500 kW average. Possibly so, as their battery pack has a built in air conditioner to prevent cell over heating. Likely 500 kW would damage the connectors between car and charger. Worse the power company would charge plenty to run in power lines capable of suppling 1/2 megawatt a few hundred minutes per month = very low use of demand. Like most websites the amount of useful details is decreasing. Possibly they tried it and discovered that fast a charge reduced battery life expectancy even if the cells didn't get hot. It would destroy lead acid batteries in seconds. Some private homes have 50 kW available = 240 volts at 208 amps, but it is likely illegal to get the power directly from the main 300 amp circuit breaker. I suspect the Leaf and most competiters can be charged with 10 kWh with an appropriate charger in less than one hour, but have not seen any claims. Above 90% of full charge, I believe all batteries need to be charged slowly, but determining the 90% point is sometimes evassive. Also batteries are less tolerant of high charging rates, near the end of their useful life. Neil

Did you miss the discussion of the last couple pages? We talked about using on-site energy storage for load-leveling on site to minimize load on the grid, or on-site power generation. That also makes me consider another idea. Partitioning the batteries so that you can charge each one separately in parallel. Also, I wonder if super/ultra capacitors might be used to speed along rapid-charging and release that electricity to the battery more slowly after disconnection, allowing for quicker recharging stops. Don't they already use these for regenerative breaking on some cars?

Some of the links I listed show how a 24kWh battery (Nissan Leaf) can be charged to 80% in 25-30 minutes and one even demonstrated such rapid charge technology that was already in the field. It's called CHAdeMO and it used 480VDC from a three phase 480v connection to the grid. This commercial charger isn't theoretical, it's already being sold and used. See my previous links. I posted another link about L-Ion batteries (general) and they can be rapid charged to about 80% and then they need a long, slow saturation charge. L-Ion is also stressed by temperature, possibly having issues with both cold and warm temps. The one link references colder than optimum temps during their trial. You can google Arizona and Nissan Leaf to find articles about problems with high temps.

[starcanuck64]

Also, I wonder if super/ultra capacitors might be used to speed along rapid-charging and release that electricity to the battery more slowly after disconnection, allowing for quicker recharging stops. Don't they already use these for regenerative breaking on some cars?

I was also wondering about this use of EDLCs in series with batteries, they can help extend battery life and provide a quick charge option.

Looks like Mazda is introducing a capacitor based regenerative braking system:

http://www.mazda.com/publicity/relea...1/111125a.html

'i-ELOOP' features a new 12-25V variable voltage alternator, a low-resistance electric double layer capacitor and a DC/DC converter. 'i-ELOOP' starts to recover kinetic energy the moment the driver lifts off the accelerator pedal and the vehicle begins to decelerate. The variable voltage alternator generates electricity at up to 25V for maximum efficiency before sending it to the Electric Double Layer Capacitor (EDLC) for storage. The capacitor, which has been specially developed for use in a vehicle, can be fully charged in seconds. The DC/DC converter steps down the electricity from 25V to 12V before it is distributed directly to the vehicle's electrical components. The system also charges the vehicle battery as necessary. 'i-ELOOP' operates whenever the vehicle decelerates, reducing the need for the engine to burn extra fuel to generate electricity. As a result, in "stop-and-go" driving conditions, fuel economy improves by approximately 10 percent.