With the electrification of the automobile gaining momentum each day, a dizzying variety of hybrid, plug-in hybrid and pure electric drive systems are heading to market in coming years.
With each new model, consumers will grasp for precedents. Is that new electric-drive vehicle most like a battery-powered Nissan Leaf or a Chevy Volt plug-in hybrid? Or is the Toyota Prius gas-electric the right benchmark?
When it comes to the BYD F3DM, a Chinese car expected to go on sale in the United States early next year, the right answer may be, “All of the above.”
The F3DM starts with the platform of the front-drive BYD F3, China’s proven best seller, and adds a 16-kilowatt-hour battery pack and two alternating current electric motors. Its operation is sometimes closest to a pure electric vehicle; at other times it’s closer to a conventional hybrid. BYD calls it a dual mode — the DM part of the F3DM name.
BYD engineered the car to drive mostly on electricity. After an overnight charge of the battery pack, drivers will punch the dashboard E.V. button and drive off using only energy from the lithium-iron-phosphate battery. This chemistry is not as effective at storing energy as the lithium-manganese formulas used in the Leaf and Volt, but BYD says it makes the tradeoff in the interest of safety and durability. For simplicity and cost containment, the F3DM does not have an active thermal management system for the battery — something that the Volt engineers say is crucial to cell longevity.
The motors are a 50-kilowatt unit that drives the wheels and a 25-kilowatt helper that can send power to the wheels or generate electricity through regenerative braking. As long as the charge level of the F3DM’s batteries is above 20 percent, the two motors handle all the work; 30 miles or so down the road, the car automatically switches from E.V. operation to hybrid mode.
At that point, the F3DM’s 1-liter 3-cylinder engine is called into service to bring the battery charge as close as possible to 30 percent, effectively extending the range of the vehicle by hundreds of miles, just like the Chevy Volt.
There is a direct connection between the gas engine and the wheels, a Prius-like approach that comes in handy when accelerating onto a highway. In high-load circumstances, the 68-horsepower gas engine combines with the electric motors for a total of 168 horsepower.
The size of the battery pack matches the Volt’s capacity at 16 kilowatt hours. Yet, there are major differences. The F3DM uses 100 3.3-volt cells stored under the cabin; the Volt uses 288 lithium-manganese-spinel cells arranged in a T-shape down the vehicle’s center.
The F3DM’s 1-liter 3-cylinder engine is a pipsqueak, but perfectly suited for its primary role of recharging the batteries. BYD showed a bit more flair by including a rooftop solar panel as a standard feature. It’s more show than substance, but does provide some electric energy to run vehicle accessories like the radio and climate control. In the end, the solar panel probably doesn’t add much cost, because BYD is one of the world’s largest manufacturers of photovoltaic cells, in addition to being a global leader in lithium-ion batteries.