Slow your car, recharge your batteries

Posted by Joel Arellano, EarthTechling

The Cadillac ELR is the luxurious sibling to the more pedestrian Chevrolet Volt. Recently, General Motors released info on the ELR’s "Regen on Demand," a feature unique to the latest Caddy.

When a driver presses the brakes in a conventional, fossil-burning vehicle, the kinetic energy is wasted as heat in the brake pads. Hybrid and electric vehicles (EV), on the other hand, use braking systems that convert the energy into electricity which is then used to recharge the vehicle’s batteries.

The Cadillac ELR builds on this well-known principle with Regen on Demand. First, the driver removes his or foot off the accelerator. The EV begins to coast. The driver then toggles the paddle shifters on the steering wheel to activate the system. (In most autos, paddle shifters are used to manually row through the gears in the transmission.) Regen on Demand starts converting the kinetic energy into electricity. According to Cadillac, the system, when turned on, makes the ELR driving experience feel something like downshifting in a manual-transmission vehicle. It also offers similar control and performance by such transmissions.

Says Chris Thomason, ELR chief engineer over at Cadillac: “Pulling back on the paddle to slow down allows the ELR driver to keep their foot close to the throttle, ready to accelerate. It provides a more engaged, satisfying driving experience, and when you consider the added benefit of re-capturing energy, it’s also a smart thing to do.”

Like the Volt, the Cadillac ELR is powered by a 154 kW electric motor and lithium-ion batteries that provide 16.5-kWh of electricity. When the batteries charge begin to run low, the 1.4-liter four-cylinder gasoline engine kicks on, turning the 55 kW generator to recharge them. These batteries can also be recharged through a standard 120 V outlet, which takes around 12 hours to reach full capacity, or through a dedicated, 240 V charger, which cuts recharge time to roughly 4 – 5 hours.

GM has not released fuel economy figures, pricing information, or performance data (i.e., zero to 60 mph) on the coupe at the time of this post. The Cadillac ELR is scheduled to go on sale next year.

* Joel Arellano, EarthTechling