The control of battery thermostatic in full electric vehicle includes two aspects. One is warming the electric vehicle battery package in the severe cold districts in the winter to reduce discharge velocity in low temperature conditions and increase the battery’s endurance. The other is cooling the battery package in the high temperature districts in the summer to slow down the aging velocity of inner units in high temperature environment and prolong the using lifetime. Targeted on the problem of energy battery in full electric vehicle

the method for controlling battery temperature using assistant thermostat is proposed?—liquid constant temperature control method. A set of devices which could modulate the battery package temperature through the air conditioning and heating system is established so that the battery package can work well in any weather conditions. The water heating method

which makes use of antifreeze solution in the water storage tank whose temperature is modulated by PTC(Positive Temperature Coefficient) thermostat

is used for heating; the refrigerating fluid –R134a is used for cooling. The thermostat’s construction and working principle are introduced. Finally

the performance and feasibility of the thermostat are analyzed through testing and simulating.