Ford Uses Liquid-Cooled Battery System to Help Focus Electric Owners Maximize Range
Ford announced that the all-new Ford Focus Electric, which debuts in late 2011 in the U.S. and 2012 in Europe, will be powered by a lithium-ion battery system that utilizes cooled and heated liquid to regulate battery temperature, extend battery life and maximize driving range. The thermal management technology helps the Focus Electric operate efficiently in a range of ambient temperatures.
The all-new Ford Focus Electric, which debuts in the U.S. late next year and in Europe in 2012, will be powered by an advanced lithium-ion battery that utilizes heated and cooled liquid to help maximize battery life and gas-free driving range.
Thermal management of lithium-ion battery systems is critical to the success of all-electric vehicles because extreme temperatures can affect performance, reliability, safety and durability. Ford has chosen an advanced active liquid-cooling and heating system to regulate the temperature of its lithium-ion battery packs, which are designed to operate under a range of ambient conditions.
"All-electric vehicles do not have a conventional engine on board, so it is critical we maximize the performance of the battery under various operating temperatures," said Sherif Marakby, Ford director, Electrification Program and Engineering. "Active liquid systems are more effective than air systems at regulating lithium-ion battery temperature. As a result, the active liquid system on Focus Electric will play a key role in providing our customers with the best performance possible."
The active liquid cooling and heating system also enables the Focus Electric to automatically precondition the battery pack temperature during daily recharging. When the vehicle is plugged in to the power grid, the vehicle system will be able to warm up the battery on cold days and cool it down on hot days. The vehicle will have an expected range of up to 100 miles and use no gasoline at all.
While air-cooling methods work well for many of today’s smaller car battery systems, the larger, more complex lithium-ion battery technology powering Ford’s all-electric vehicles calls for an aggressive thermal management system. An active liquid system heats or chills a coolant before pumping it through the battery cooling system. This loop regulates temperature throughout the system against external conditions.
On hot days, chilled water absorbs heat from the batteries, dispersing it through a radiator before pumping it through the chiller again. On cold days, heated water warms the batteries, gradually bringing the system’s temperature to a level that allows it to efficiently accept charge energy and provide enough discharge power for expected vehicle performance.
The liquid cooling system also plays a role in charging the vehicle. When the all-electric Focus is plugged in to recharge, the vehicle control system will automatically precondition the battery, if needed, to the optimal temperature before accepting charge. If the battery is already at the optimal temperature, the system will automatically accept charge and maintain an optimal temperature.