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Nearly a hundred years ago, a deal between Henry Ford and Thomas Edison to make electric cars fell apart because 1914 battery technology wasn't up to the job. From then on, cars ran almost exclusively on gas, driving us straight into our current global warming mess. Now, Ford has joined companies like Tesla and Chevrolet to finally build electric vehicles en masse. Toyota started the craze with its gas-electric hybrid Prius, while Tesla's Elon Musk ditched hydrocarbons altogether with the all-electric Model S. Plug-in hybrids, meanwhile, are a shotgun marriage between the two -- but Toyota's plug-in Prius hybrid is drastically differently than Chevy's Volt. So why all the different technology? Let's go for a tour of the latest in electric and hybrid car tech.

WHAT IS IT?

Electric cars go way back to the early 1800s, but the first practical one was invented by English tram magnate Thomas Parker in 1884. EVs had a mini golden age at the turn of the century, peaking in 1912 when 34,000 were produced in the US alone -- about equivalent to the entire hybrid/electric production of 2002. Such cars were popular in cities due to their simpler operation and limited range, and were often marketed to women. With the discovery of large petroleum reserves and the development of highways, however, longer-range gasoline cars took over. By the middle of the 1910s, most companies stopped making EVs except for niche applications like forklifts or golf carts.

After that, development on electric cars virtually stopped, despite a few stunted attempts like the Henney Kilowatt. Some research and development did continue, and an early attempt at building a hybrid-electric car was AMC's Amitron in 1967: the first US car to use an energy regeneration brake. The idea was to recharge the car's battery using braking energy, and was later pursued in several experimental vehicles from Audi, Volvo and others.

Stuffing the gasoline genie back in the bottle hasn't proven easy, even though modern electric cars are superior in nearly every way. EV drivetrains are infinitely simpler, since they don't need complex transmissions, liquid cooling and other accessories. EVs are also far more efficient, using around 90 percent of the power stored in their batteries, compared to 30-35 percent for a gas vehicle. In fact, EVs could be built for a fraction of the cost of gas cars, except for one problem: the batteries, which are pricey and can only store 5 percent of gasoline's energy by weight.

The best batteries for cars today are lithium-ion models (similar to what you find in many laptops), which have decent energy density, but are expensive and highly flammable. For instance, it's estimated that the Tesla Model S battery runs about $15,000, about a fifth of its $70,000 purchase price. (Tesla wants to get that down to $8,000 with its upcoming Gigafactory.) New tech to make batteries more efficient and cheaper is tantalizingly close, but still hasn't been commercialized.

WHO ARE THE EV AND HYBRID PLAYERS?

Hybrid's Birth

Toyota started the hybrid craze with the Prius, which launched with fanfare to the Japanese market in 1997 (seen above next to the very nervous-looking, then-Toyota President Hiroshi Okuda). The car was a rousing success in its home country, exceeding Toyota's expectations with sales of 18,000 units in the first year alone. Meanwhile, other carmakers launched all-electric EVs in the US between 1997 and 1999, but they sold poorly and were quickly dropped. Honda was actually first to the US with a hybrid in 1999 -- the two-door Insight -- while Toyota's Prius hit US shores the next year.

With the Insight and Prius sporting 61 and 52 mpg (EPA) in the city, respectively, hybrids became the go-to cars for the green set. Prius sales topped the 2 million mark in 2009, and most other manufacturers subsequently launched hybrid-electric cars, including Ford, Chevy, Volkswagen and even Porsche.

Meanwhile in 2008, PayPal magnate Musk launched Tesla's all-electric Roadster, the first production car to use lithium-ion batteries. Though the company didn't even build the chassis (it was based on a Lotus Elise), other manufacturers like Chevy said the Roadster inspired them to pursue their own commercial EVs. As a result, the Chevy Volt (a hybrid EV) and Nissan Leaf (a pure EV) were both launched in 2010, followed by Volvo's C30 Electric, the Ford Focus Electric, BMW's ActiveE, the Toyota RAV4 EV and others. Tesla itself launched the Model S in 2012, arguably the most famous electric car of them all (above).

HOW DO HYBRIDS WORK?

All hybrid and electric vehicles use regenerative braking to recover braking power and store it in the battery. But there are several hybrid drivetrains used in modern hybrid and EVs. Parallel hybrids, like Honda's Civic and Insight, are gas-powered cars with a small electric motor connected in parallel with the internal combustion engine (ICE) to the transmission. Such vehicles operate efficiently at highway speeds, but less so for stop-and-go driving.

The Chevy Volt (above) is an example of a "series" plug-in hybrid vehicle. The car's drivetrain is purely electric, and the gas engine merely recharges the battery via a generator. Because of the efficiency lost during recharging, series hybrids are less efficient on the highway, but better for stop-and-go city driving. Lastly, cars like the Toyota Prius use a combination of series and parallel systems to operate efficiently at both city and highway speeds -- but cost more due to the extra parts.

Plug-in hybrids like the Chevy Volt or Toyota Prius Plug-in Hybrid are hybrids with a charging port and battery large enough to allow for all-electric motoring over longer distances. The Prius, for instance, can go 11 miles on a three-hour charge from a regular outlet, while the Volt can do 38 miles on a 10- to 16-hour charge.

HOW ABOUT EVS?

EVs are simpler, but the drivetrain, battery and charging designs vary widely. The Tesla Model S is a rear-engine, rear-wheel-drive vehicle with a single electric induction motor, while the Nissan Leaf is a front-engine, front-wheel-drive vehicle with a synchronous electric motor. At the extreme end, the Mercedes-Benz SLS AMG Electric Drive (the gorgeous car above) has four electric motors, one at each wheel, producing about 740 horsepower total.

Most EVs can be charged to a near-full battery overnight from a standard socket, or charged in about half that time at 240 volts. The Tesla Model S has an optional dual charger that produces 58 miles of travel per hour of charge. Tesla also offers free Superchargers that can charge a battery half-full in 20 minutes at 103 stations around the US, with many more planned. Also, with Tesla again, the battery can be replaced in 90 seconds with a full one at select service stations.

WHY SHOULD I CARE?

Fossil-fuel powered cars have played a huge role in rising temperatures, acidification of oceans and other nasty environmental side effects. They've also given the US a heavy foreign oil habit, and the sellers aren't always friendly countries.

But even if you don't care about geo-politics, greener cars have numerous benefits. Certain hybrid models are now cheaper to run than their non-hybrid counterparts, according to the US Department of Energy. EVs can be made quieter than gas cars, thanks to the lower weight and lack of internal combustion. The entire front of an electric car can be a crumple zone, making them safer in collisions. And you can often legally drive an EV or plug-in hybrid in an HOV lane, even if you're alone.

Pure electric cars and plug-ins have much higher prices (those big batteries again), making savings harder to come by. You can, however, get federal tax credits of $7,500 for most EVs and some plug-in hybrids like the Chevy Volt, with states like California kicking in up to $2,500 for EVs and $1,500 for plug-in hybrids as well (that's on top of the US government's tax credits). For instance, Nissan's Leaf runs about $30,000, but that price can tumble to $20,000 after federal and state rebates. And Nissan says you'll save about $4,000 in gas over a five-year period, making the effective price around $16,000. And maintenance? It's hard to say since EVs haven't been on roads for long, but the vehicles are much simpler and should eventually become cheaper to keep up.

WHAT'S THE ARGUMENT?

There are some sticky issues with electric and hybrid vehicles. The batteries don't last forever, are hard to dispose of and expensive to replace. The Nissan Leaf's heat-resistant battery packs (above) are $5,500, for example, while Tesla's Model S battery is estimated to cost $12,000-15,000 to replace. Both of those cars have eight-year warranties on the batteries, but the charging capacity diminishes considerably after several years. Due to their immaturity, both hybrids and EVs are (currently) expensive to maintain. Finally, depending on where you live, the eco-friendly aspect of EVs is questionable. If your electric grid is powered by coal, and you're charging an EV from that grid, you're still contributing to global warming. Nuclear plants have a whole other set of pollution issues.

As the number of hybrid/electric vehicles on the road increases, the prices for both batteries and maintenance is falling. Tesla plans to reduce the price of its Model S battery to $8,000 or so at its Gigafactory with Panasonic. New battery science -- like recent lithium anode advances -- will eventually be commercialized, reducing weight and cost. In only a few years, EVs and hybrids have evolved considerably, with better batteries, endurance and power. All that has come about because regulations, rebates and competition have motivated carmakers to push the state of the art. Prices will continue to fall, and eventually be cheap enough that government EV incentives can be dropped altogether. When that happens, everybody wins.

WANT EVEN MORE?

BMW unveils i3 electric car in the carbon fiber flesh

You can't touch your keyboard without tripping on a website about EV and hybrid vehicle tech, thanks to sky-high levels of interest. But there are a few standout sites: our sister blog Autoblog has its Autoblog Green site, detailing all things EV and hybrid. There's also Green Car Reports, Clean Technica and Hybrid Cars. Most car builders have both hybrid and EV models nowadays, as well, but a few standouts are Nissan's Leaf, the Ford Focus Electric and Fusion Hybrid SE, the Chevy Volt and the Tesla Model S. To find out if you can actually afford any of those, the US Department of Energy's hybrid calculator is pretty handy and there's a list of federal rebates for EVs and plug-in hybrids. The Plug In America coalition has a handy map of state tax rebates. Lastly, check right here: We cover hybrid and especially electric vehicles galore.

[Image credits: (Honda Plug-in Hybrid): Yoshikazu Tsuno/AFP/Getty Images, (Toyota Prius Launch 1997): AP/Tsugufumi Matsumoto, (Tesla Model S): Tesla Motors, (Volt drivetrain): Chevrolet, (SLS Mercedes AMG Electric Drive at Paris Auto Show): Wikipedia/Lebubu93, (Nissan Battery Pack): Nissan Motors, (BMW i3 Electric): BMW]