2017 BMW i3Enlarge Photo
The area of electric-car charging has its own, remarkably arcane language for referring to different types of charging. Every electric car comes with a charging cord that lets it recharge from conventional wall sockets in the country where it was sold. That's the slowest way to recharge.
Level 1 charging: The slowest type of recharging, which may take up to a full 24-hour day in electric cars with larger battery packs. In North America, Level 1 charging uses electricity from a conventional wall socket at 120 volts.
Level 2 charging: This type is faster because it uses higher voltage, 240 volts in North America, and runs at up to 50 amperes of current. Home charging stations use this standard, as do most longer-term (more than 30 minutes) public charging sites.
J-1772 connector: This is the name of the standard plug and socket used for Level 1 and Level 2 charging in all electric cars sold today in North America except Teslas, which offer a J-1772 adapter.
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DC fast charging: This is the fastest way to recharge an electric car, usually bringing the battery back to 80 percent of its capacity in 30 to 60 minutes. (Note it's sometimes incorrectly called "Level 3," but that's not an internationally adopted standard.) There are three incompatible connectors for fast charging today, though a few converters exist between some of the pairs.
CHAdeMO: One of two internationally accepted DC fast-charging standards, it was developed in Japan and used primarily in North America by the Nissan Leaf, as well as the Mitsubishi i-MiEV and the Kia Soul EV.
Combined Charging System or CCS: Also known as "SAE Combo," this is the standard used by all German makers and all U.S. makers except Tesla. It's an expansion of the J-1772 plug used for Level 1 and Level 2 charging, rather than an entirely separate connector as CHAdeMO is.
Chargeway electric-car charging symbols for Chevrolet Volt, BMW i3, Nissan Leaf, Tesla Model SEnlarge Photo
Hybrid vehicles generally use one of three different methods for supplying power to the wheels.
BAS: Belt Alternator/Starter - A parallel system used by mild hybrids that provides some fuel savings (not nearly as much as a full hybrid) at a relatively low cost. BAS systems use a large alternator connected by a serpentine belt to the crankshaft. This allows the gas engine to stop and then quickly restart (at stop lights for example) and also provides some assistance to the gas engine for moving the car. The main seller of such systems has been General Motors in a variety vehicles across three generations of the system.
Parallel Hybrid (also known as "blended" HEV). Parallel hybrid electric vehicles use a drive system where one or two electric motor-generators and a gasoline engine can send power to the drive wheels in combinations carefully optimized by the powertrain control electronics. Virtually all hybrids use blended systems.
Series Hybrid, also known as Range-Extended Electric Vehicle (see above). A series-hybrid vehicle uses only the electric motor to power the wheels; the gasoline engine serves as a back-up. When the battery is depleted, the gasoline engine switches on to run a generator that in turn supplies power to the drive wheels.
Scene from 2017 Karma Revero television spotEnlarge Photo
The Chevy Volt is the best example of a series hybrid, but there's an asterisk there: Under some circumstances, engine output can be diverted from the generator to power the front wheels directly. The BMW i3 REx, on the other hand, has no mechanical connection at all between its engine and drive wheels. Nor does the Fisker Karma (now Karma Revero). Series hybrids have been used for decades in boats and trains.