[CREWZIN]

I did a search and it seems the only blankets on the market are the ones you plug in for around $30. Looks like you just have to stop by a Chrysler dealer and see if they can look it up. I did find this during my search......

On gasoline engine equipped vehicles a flexible thermal guard wraps around the battery case to enclose the sides of the battery. The thermal guard consists of a plastic cloth outer skin with a polyester based insulator fiber. The thermal guard protects the battery from engine compartment temperature extremes. The temperature of the battery can affect battery performance. The air trapped in the thermal guard creates a dead air space, which helps to insulate the sides of the battery case from the air temperature found in the surrounding engine compartment. When replacing the battery, the thermal guard must be transferred to the new battery. The list price on a replacement cover is approximately $8.