Charging Electric Vehicles in Motion

distance on a single charge. If you've got a battery full of juice and take off on a road trip, what happens when you start creeping up on that last bit of energy left in the battery. You might find a charging station, but how long will it take you to get your battery back up to speed. Gas powered vehicles are easy to refuel. It takes a few minutes and then you're back on the road, But most electric

vehicles require hours of recharging. That's not a big deal if you're using your car for basic commutes and you can recharge at the end of each day, But for road trips, what are your solutions? One route is to create fast charging stations. Tesla, which helped propel electric vehicles into the mainstream consciousness, touts its supercharger stations as the world's fastest. According to the company, you can get your vehicle up to a full charge in just half an

hour using a supercharge station. Tesla has even created a program in which Models and Model X owners get credits equivalent to a thousand miles of travel on supercharge refills every year. The company also states that if you were to use up all your credits in a year, you'd still only pay a fraction of the cost of filling up a tank of gas at a supercharging station. Still, half an hour of white time is too long for some people, and the only other option is to swap

out batteries in some sort of pit stop. Right, not quite. There's another solution that doesn't require cables or supercharging stations, and the right implementation, it doesn't even require a driver to stop his or her vehicle to charge. The secret to this sorcery is inductive coupling. The idea is not new. Michael Faraday got the basic idea back in the mid nineteenth century. It all has to do with electromagnetism. Basically,

the relationship goes like this. If you take a conductive material such as some insulated copper wire, and you move that material through a magnetic field. The magnetic field will induce a current to flow through the copper wire. To make this a persistent effect, you either must continuously move the copper wire in and out of the magnetic field,

or cause the magnetic field itself to fluctuate. In other words, a steady magnetic field will only induce current to flow through a conductor when the conductor initially enters that field. There are different ways to cause a magnetic field to fluctuate. One is to use an electro magnet with an alternating current. Electromagnets generally consist of a conductive material, such as copper wrapped around a fare right core. You may have made a basic electro magnet in class by wrapping a copper

wire around an iron nail. Running a current through the copper wire by attaching it to a battery turns it into a magnet. Batteries provide direct current. However, if you attach an electromagnet to a source of alternating current, the electricity will flow one direction in the wire before reversing and going the other direction. It will do this thousands of times per second. The magnetic field will change as the direction of electricity flow changes. While you have yourself

a fluctuating magnetic field. Now, imagine you take a bunch of conductive copper wire and you create a pad that can go on the bottom of an electric vehicle. When that copper wire encounters a fluctuating magnetic field, it will cause current to flow through the wire. Attach that wire to your electric vehicles battery system, and the battery can store that electricity. Generally speaking, the way this could work

for cars requires a lot of work. You need to install the electro magnets and power systems under the surface of the street. That usually means digging up existing streets to lay down the technology and cover it back up with asphalt. A basic implementation of this technology might only exist at intersections or special parking spaces where a car could spend some time idle. Any vehicle outfited with the proper charging apparatus could benefit from such a system. This

would extend the range of any electric vehicle. If you wanted to make your system to work with cars that are actually in motion, you need to cover a lot more ground. A car traveling at a good speed won't spend enough time over any small segment like an intersection to benefit very much. Instead, you need to outfit hundreds of feet of street with these electro magnets so that the electric vehicles traveling down the stretch could get enough

of a jolt of juice to make a difference. There are some big barriers to implementing this sort of strategy, namely time and money. Road construction can take a long time and tends to be extremely disruptive while it's happening, and it isn't necessarily the cheapest of activities, But once installed, such an infrastructure could be an enormous benefit to electric vehicle drivers. We may see these systems put in place

in a few different parts of the world. There are research projects in Israel and France that are exploring opportunities that would allow electric vehicle drivers to charge on the go. Stationary solutions are popping up as well. They might require someone to stop for a few minutes over a specific stretch of pavement, but that is still more convenient than having to plug a vehicle in with a physical cable.

This coupling strategy is an effective way to transmit power over short distances, but even relying upon advanced technologies that pair resonating components to boost efficiency and range, there are limitations to this approach. We're not likely to see Nicola Tesla inspired towers broadcasting power across miles. It's just not a practical or efficient means to transmit power. But it might end up removing one of the reservations some people

have about electric vehicles. To learn more about electro magnets, electric cars, and all things technological, subscribe to the tech Stuff podcast. We explore tech in greater detail. Over there, I'll see you against him.