Self charging engine heater

#This invention relates to engine heaters used for cold weather starting of motor vehicles. More particularly this invention relates to a thermostatically controlled and time programmed block heater which operates without the necessity of a power source adjacent to a parked vehicle.

#After cold nights or during winter nights in cold climates vehicles start much more quickly and easily if they are pre-heated. Cranking a cold and unlubricated engine significantly wears and reduces the life of the engine. Furthermore, a pre-heated engine reaches operating temperature relatively quickly so that the interior passenger compartment of the vehicle can be defrosted and warmed. A pre-heated engine is a convenience which is much desired in cold weather.

#One problem with preheating vehicles is that a cold morning must be anticipated so that the vehicle may be plugged in the preceding night. In very cold climates power is not available everywhere. The vehicle may be fully chilled after a day's work. Plugging the vehicle into a power source is not always possible and when it is possible, excessive energy may be dissipated if the vehicle is plugged in long before use.

#FIG. 1 is a diagrammatic view of a method of preheating a vehicle engine utilizing a second battery to power a vehicle heater.

#The following is a discussion and description of the preferred specific embodiments of this invention, such being made with reference to the drawings, wherein the same reference numerals are used to indicate the same or similar parts and/or structure. It should be noted that such discussion and description is not meant to unduly limit the scope of the invention.

#Turning now to the drawings and more particularly to FIG. 1 we have a diagrammatic view of a method of preheating a vehicle engine E utilizing a second battery B2 to power a vehicle heater 22. This method eliminates the necessity to anticipate and persistently plug into a power source adjacent to wherever the vehicle V may be parked. Most basically the method of preheating a vehicle engine E having a first battery B1 charged by an alternator A comprises the steps of: providing for a second battery B2 electrically also charged by the alternator A, said second battery B2 electrically isolated from the first battery B1 by a battery isolator BI, so that the first battery B1 is not depleted by a load drawn from the second battery B2; and, providing an engine heater 22 which draws power from the second battery B2.

#A preferred aspect of this invention comprises a method as above further comprising the step of providing a thermostatic switch 26 serially connected between the second battery B2 and the engine heater 22 so that the heater 22 receives power only when the ambient temperature drops below a specified temperature. It is also preferable to additionally include the step of providing a timer 28 serially connected between the second battery B2 and the engine heater 22 so that the engine heater 22 is powered only at preset times programmed on the timer 26 immediately in advance of use of the vehicle V.

#In the most preferred aspect of the invention, the thermostatic switch 26 and the timer 28 are an integral unit TTC. The engine heater 22 is powered in advance of use times specified by the user on the timer 26, and wherein the engine heater 22 is automatically programmed by the TTC to be powered on for varying amounts of time in advance of the specified times of use dependent on the ambient temperature.