If you always connected your vehicle's battery to a charger every time you parked your car, you'd always be guaranteed that you'd have enough voltage/amperage to start your car later on, even in the coldest weather.
However, doing so is generally quite inconvenient; you would have to open the hood (bonnet to uk folks), and put the charger clamps onto the battery each and every time you parked, and remove them whenever you wanted to leave.
If there were an external charging port, perhaps one on each of the front and rear bumpers, on the undersides, then you could plug the charger into whatever side of the car is facing towards the rear wall of the garage... without opening any part of the vehicle.
And if the plug were connected to this port via some sort of pullaway magnetic mechanism, then you could pull the car out of the garage, and the plug would detach itself without damage, without you needing to explicitly unplug it.
And last but not least... if the charger had some sort of car detector (or rather, a charging-port detector), it could automatically reach out with the plug (on the end of some sort of robotic arm), and stick it on the socket, any time you parked in the garage.
There are two groups of vehicles that this would be good for:
The first group, electric vehicles and plugin hybrids, for obvious reasons.
The second group, conventional vehicles, to keep the battery warm, to operate a built-in engine block heater, and to operate an electrically powered cabin air heater or air conditioner.-- goldbb, Jan 11 2010 For a home installation, both the recharger and the block heater (and the cabin heater) would best be served by a timer, ie: you don't need the vehicle warmed up until you want to drive it. Likewise, in cold weather you might be better off leaving charging the battery 'til the last minute as well (?)-- FlyingToaster, Jan 12 2010 Cute, but I'm not certain I would want a robot with a live 110 to reach out of my garage feeling around for a car to plug in to.-- RayfordSteele, Jan 12 2010 RayfordSteele, you have an electric car? Cool!
If the system were being used with a conventional car, the plug being waved around by the robotic arm would be of the 12 volt variety. This is a low enough voltage that the risk of electric shock is quite low.
For electric cars or plugin hybrids, the plug would be insulated / shielded in such a way as to prevent anyone from accidentally getting electrocuted.-- goldbb, Jan 12 2010 Yes I do. It also has a remote control and runs on 9 volts.
Oddly, I will be starting a grad course in hybrid battery technology this week, and so will likely be driving around in a test vehicle at times.
The MIT team is working on an appropriately-named Ford Fusion that will charge in less than 10 minutes. Trick is it needs like 350 volts at 1000 amps to do so. That's enough juice to fuse anything. Don't ask me how they manage to not melt their collection of little Lithium-Iron batteries into a puddle with that...-- RayfordSteele, Jan 13 2010 / it needs like 350 volts at 1000 amps to do so/
That is what has always worried me about the concept of electric car charging stations. To charge in a decent time the power (and therefore current) has to be too high for me to want anything to do with the contacts-- sneakythumbs, Jan 13 2010 RayfodSteel, for a toy RC car, it would probably be easier to design the car to plug itself into the charger (like a Roomba) instead of having the charger plug itself into the car.
As for the Ford Fusion -- from what I understand, the 2010 Ford fusion is a hybrid, but not a plug in hybrid. Where do the numbers you quoted come from?-- goldbb, Jan 13 2010 My grandfather halfway-baked the posted idea. He had a trickle-charger mounted under the hood, along with a block heater; the power cord dangled under the front bumper with a short piece of chain attached to the plug. An outlet was mounted on a post at the front of the driveway. After parking, he'd plug the car in by hand, but on leaving, the car would unplug itself.-- lurch, Jan 14 2010 how about this: wireless. just park in a certain spot, kinda like the powermat for phone charging but bigger. (1/2 of the transformer is in the floor, the other half under the car)-- AutoMcDonough, Mar 03 2010 Even if the connectors used for charging will allow a really big amount of power to flow through them, I see no particular difficulty with making them safe. Use a solenoid-operated switch (otherwise called a contactor) on each end of the main power wires, and have a few smaller contacts carry validation signals. No significant power will be available at either connector until both systems have confirmed that the connector has been properly installed.-- supercat, Mar 03 2010 random, halfbakery