Patent ID: 7782021

Claim:
A method of charging a battery within an electric vehicle utilizing a battery charging system, the method comprising the steps of: continuously determining an instantaneous charging cost rate, wherein said instantaneous charging cost rate is continuously determined as a function of time; determining a charging schedule that includes at least a first time period and a second time period, wherein said first time period precedes said second time period, and wherein a charging stop time is anticipated to occur within said second time period; initiating battery charging within said first time period whenever said instantaneous charging cost rate is less than a threshold cost rate; pausing battery charging within said first time period whenever said instantaneous charging cost rate is greater than said threshold cost rate; resuming battery charging within said first time period whenever said instantaneous charging cost rate is less than said threshold cost rate; terminating battery charging within said first time period after said battery reaches a first energy stored level; initiating battery charging within said second time period regardless of said instantaneous charging cost rate; and terminating battery charging within said second time period after said battery reaches a second energy stored level, wherein the second energy stored level is higher than the first energy stored level.