DEARBORN, MI — Ford Motor Company's all-electric Focus will use liquid instead of air to cool and heat the car battery in order to maximize the battery's life and driving range.

The Ford Focus Electric, which comes out in the U.S. in late 2011 and in Europe in 2012, features a lithium-ion battery system, which needs to be kept in a certain range of temperatures to optimize its performance and durability.

While air is sufficient to regulate battery temperatures in smaller battery systems, Ford says, liquid works better to meet the Focus' needs.

The liquid system works by cooling or heating water, based on the outside temperature, then pumps it through the battery's cooling system. In hot conditions, the cool water pulls heat from the battery; on cold days it uses hot water to bring the battery's temperature up to the level needed to provide enough power to the vehicle.

When the Focus is charging, the liquid system will either bring the battery to the optimal temperature or maintain the temperature.

_{Ford Focus - CC license by Flickr user futureatlas.com}