This Idea was inspired by the recent "Batteryless Electric Vehicle" Idea (linked). It proposes putting the battery for an electric vehicle in a trailer.
That Idea has at least one advantage and disadvantage that wasn't stated. The disadvantage is "extra moving parts", most notably the wheels of the trailer. Such parts are always associated with extra friction and mechanical-energy losses. But the advantage is that the vehicle-and-trailer combination can be lower-to-the-ground and so more aerodynamic. You HAVE noticed, haven't you, how cars like the Prius look so bulky they can't possibly have really good aerodynamics?
So, in this Idea the proposal is simply to stretch the car. No, not stretched so much as a "stretch limosine". A modest amount of stretch should easily make room for the battery pack, and that pack should be as easily removable as if it had been attached like a trailer.
Imagine a third door in the side of the car; just open the door, move a sort of "gurney" up to the doorway, lock its wheels, and pull out the battery pack onto the gurney. A second gurney can bring your car a freshly-charged battery pack, so your time at the "filling" station is very short. The station obviously charges many battery packs while cars are mostly not there. Standardized battery packs are the way to go, obviously!
Meanwhile, the car can still be reasonably sleek and low to the ground, for good aerodynamics. And, of course, there are no extra moving parts, with respect to existing electric vehicles.-- Vernon, Nov 09 2011 Batteryless Electric Vehicle Batteryless_20Electric_20VehicleAs mentioned in the main text. [Vernon, Nov 09 2011] Practical Electric Car Infrastructure Practical_20electri...ar_20infrastructureI have since realized that there is no such thing as a practical electric car. But the Tesla Roadster is cool. [DIYMatt, Nov 09 2011] Tesla Roadster http://www.teslamotors.com/roadster [DIYMatt, Nov 10 2011] Tesla Heavy Tesla_20HeavySame idea, except use a prestretched car called a truck. [bungston, Nov 10 2011] Flat Square Batteries Flat_20Square_20BatteriesAs mentioned in an annotation. For cars a battery pack need not be flat, but it certainly should be easy to replace. [Vernon, Nov 17 2011] Battery-swap Taxis http://www.popsci.c...debut-japan?image=1From April, 2010. This concept is old news, [Vernon]. [neutrinos_shadow, Nov 17 2011] sp. vehicle-- mitxela, Nov 09 2011 Just imagine hundreds or thousands of pounds of battery squishing the occupants in a crash. Sorry, no can do.-- RayfordSteele, Nov 09 2011 Baked. Www.betterplace.com-- white, Nov 09 2011 Long cars have been made before so I can't really count that as part of the idea. As for interchangable batteries, that was halfbaked by me, and I was informed that it was halfbaked before that, and in fact it was half baked outside of the halfbakery before that, and it looks like it is at least partially baked in that link.-- DIYMatt, Nov 09 2011 [RayfordSteele], just imagine hundreds or thousands of pounds of gasoline engine squishing passengers in a crash. They solved that problem long ago, and I'm quite sure the same solution will work for battery packs.-- Vernon, Nov 09 2011 Vernon, said solution is baked, fried, and delivered for battery packs. I was objecting to your having them inserted in a door which sounded like it would be either forward or rearward of the passenger compartment, with the passengers in between a rock and a hard place.
Put them underneath, agreed, as per the GM skateboard of many years back, is the solution.-- RayfordSteele, Nov 09 2011 Why not just have vehicles pick up power from slots in the road, like Scalextric ?-- 8th of 7, Nov 09 2011 [RayfordSteele], no, the point of this Idea is to get away from making the car taller and less aerodynamic. So, proper design can ensure that if a crash occurs, the battery pack dives downward and misses the passengers (just like passengers are protected from gasoline engines).-- Vernon, Nov 10 2011 Like I said, not that much is original about "longer car". For instance, the Tesla Roadster has plenty of space for batteries with the same form as a Lotus Elise. Also, the Prius isn't tall to make room for batteries. (and FYI, the Prius is one of the most aerodynamic cars on the market).-- DIYMatt, Nov 10 2011 [DIYMatt], well, the Prius sure doesn't LOOK aerodynamic. Anyway, I'm not a fan of battery packs, because they are energetically inefficient when compared to fuel cells. Or when compared to flywheels. Or when compared to supercapacitors. It is just that if the industry goes the battery-pack route, they should do it right. Can you imagine the chaos if all gasoline cars had different sizes and shapes of openings for filling the gas tank?-- Vernon, Nov 10 2011 Low to the ground =/= aerodynamic. Lamborghini Countach Cd: 0.42. Ford Aerostar: 0.39.
Just FYI, my job is in basic vehicle architecture.
Your car is going to have abysmal dynamics from poor Cg placement.-- RayfordSteele, Nov 10 2011 But drag = Cd * frontal area. I agree, though, //low to the ground// doesn't help. Roughly circular in cross section (like a submarine) is best.-- spidermother, Nov 10 2011 A sports car that wishes to create downforce is deliberately not aerodynamic. They also tend to have more intakes for cooling.-- marklar, Nov 15 2011 'Basic vehicle architecture' means working out dimensional details of the 'big rocks' to achieve design targets and tradeoffs. We take the program's marketing goals and try to make them self-consistent, looking at things like turning circle vs. wheelbase vs. engine package issues so as to feed back where to the program where the large hurdles are.-- RayfordSteele, Nov 15 2011 [RayfordSteele] and [spidermother], it seems I misspoke a bit. By saying "low to the ground" I was contrasting that with the "bulky" description of the Prius. It should be obvious that the overall frontal area of a vehicle is not reduced if the whole thing is simply lowered closer to the ground. But if the ground clearance and vehicle width remain about the same, and the height is reduced, then that qualifies as "lower to the ground" AND reduces frontal area, therefore equating with better aerodynamics.-- Vernon, Nov 15 2011 It occurs to me that I neglected to think of one other detail, regarding gurneys and quick replacement of a vehicle's battery pack. See "Flat Square Batteries" link. The car should actually have two doors leading to the battery pack. Both would be opened and a gurney would be positioned next to each. One gurney would hold the replacement battery pack. Just push it in, and it pushes out the other pack, onto the other gurney.-- Vernon, Nov 17 2011 random, halfbakery