The power recovery system could also help shorten charging times.
Maintaining an electric vehicle’s battery in the optimum operating temperature range is essential for maximum performance and longest life. Too hot and the load is lost from the cells, too cold and the autonomy of the vehicle can decrease by up to 20 percent, while the loading sessions last much longer than it would in a warmer climate. That’s why heat pumps, devices that capture residual heat from car engine components to power other systems, have found their way into many electric vehicles in recent years. Tesla added them to the Y, 3 and S Plaid models; Polestar includes them in the PS2 model. However, GM has launched its new waste heat recovery system with the debut of its “Ultium Energy Recovery” system.
The EBU is “based on a high-quality automotive heat pump that captures and reuses otherwise wasted energy,” said Tim Grewe, GM’s director of electrification strategy. “It’s more sophisticated than the most advanced heat pump you can find in modern homes.”
A useful technology
“We could do more with this energy,” he continued, “including increasing the range of our electric vehicles, powering low-power functions, such as heating and even preconditioning our battery for faster charging and acceleration.” For an electric car like the new Hummer, the estimated 10 percent increase in range offered by this system translates into an additional range of 50 kilometers. Similarly, this heat pump is the one that drives Hummer’s Watts to Freedom launch control function, autonomously conditioning the battery temperature to the optimum level with which to draw as much current as possible, as fast as they can, to propel the 4 tons of Electric SUV from 0 to 100 km / h in 3 seconds.
“It’s one of those situations where you want to keep the engine magnets as cool as possible so you can deliver the maximum torque,” said Lawrence Zeer, GM’s energy recovery project manager. “And then you want to heat the battery, because the battery gives a little more power when heated.” Zeer also points out that given the sheer size of these batteries, it “has a lot of heat capacity.” On the other hand, the pump will automatically precondition the batteries if the driver selects a future charging station from the navigation computer and can cool the cab as easily as it heats it.
GM plans to include the recovery system in its range of electric vehicles, including the Hummer, Lyric and future Blazer EV.