For the time being, General Motors
is content to let suppliers like A123 Systems, LG Chem and Cobasys focus on cell chemistry for its hybrid
and electric vehicle
battery packs. GM
leaders like Denise Gray and Bob Kruse believe that the key to ensuring that those cells last for (essentially) the life of the car, is in how those cells are managed. One of the killers of advanced rechargeable batteries is extreme temperatures, whether too hot or too cold. In order to ensure the batteries stay in their optimal range, General Motors is taking charge of the management control systems for its batteries regardless of who supplies the cells inside. That means the battery state of charge models need to be accurate to prevent over-charging and overheating. Lithium batteries don't like cold temperatures, so when the Volt is plugged in, the battery pack will be warmed up to ensure it provides adequate performance. If the car is left unplugged during cold weather, the range extender will start up as soon as the car is turned on to help warm the battery and the car will only switch to
battery power once the internal temperature of the battery is within range.
[Source: Green Fuels Forecast