A pure plug-in EV is only a motor as well as a rack of batteries. A Hybrid is a combination of electric motor and internal combustion engine both of which can drive the wheels. Until technology and infrastructure comes along to solve the battery charging issue, the immediate solution is ER-EVs - extended-range electric vehicles. ER-EVs are essentially EVs but with an onboard mechanism of generating more electricity on the go. Generating electricity when you drive isn't a new idea, there are several types of doing it at the moment, and these are utilized in various combinations to help range-boost electric vehicles.
Regenerative braking. Similar to the same system in a hybrid vehicle, regenerative braking turns the electrical motor into an electric generator when you slow. The potential energy of the car traveling at speed is turned directly into electricity to help recharge the batteries. Unless you're completely gullible, you are aware of the idea that a perpetual motion device is impossible, so you can't drive an EV up a hill then brake all the way down the other side to recuperate 100% of the charge you used in the climb. Regenerative braking raises the range but could never fully recharge the batteries.
Internal combustion generators. If you've ever seen, heard or travelled on a train in the last few decades, you'll have experienced a diesel-electric engine at some point. These systems add a small internal combustion engine to the mix but instead than connecting it on the transmission (like a hybrid), the engine is used solely for operating a generator to recharge the onboard batteries. Imagine a golf cart with an emergency Honda power generator associated with the back of it and you obtain the picture. This is exactly what the Chevy Volt was meant to be in its original design, as said before at the top of the page. The engine recharges it, the advantage of these systems is a hugely increased range because now you're not the battery's bitch any longer - if it starts to run low. Once the engine runs low on petrol or diesel, you fill the tank.
Fisker Karma ER-EV
A good instance of this particular kind of technology was the Fisker Karma. It had two electric motors rated at a combined 402hp that drove the rear wheels, driven from the 600lb lithium-ion battery pack. Up front there was a 2 litre turbocharged petrol engine connected to a generator that came on when the battery range dropped to 15%. There is an onboard fuel tank that fed the petrol engine that, Fisker claimed, range-boosted the Fisker from a battery-only 50 miles up to 300 miles. And even for good measure, Fisker added a roof loaded with solar panels to help you recharge the battery pack too. Interestingly, the Karma did not produce enough power to run the electric motors at their full 400 hp unless the battery was full as well as the generator was running at the same time. In that case it was at the driver's command by way of a steering-wheel mounted switch that flicked it from 'Stealth' mode to 'Sport' mode.
Fisker ran into legal and financial troubles in 2013 and basically ceased trading facing financial meltdown and an inability to deliver cars on their customers.