This disclosure is directed toward predicting energy consumption of electric vehicles and, more particularly, to using variations in past energy consumption to enhance the predicting. 
Generally, electric vehicles differ from conventional motor vehicles because electric vehicles are selectively driven using one or more battery-powered electric machines.  Conventional motor vehicles, by contrast, rely exclusively on an internal combustion engine to drive the vehicle.  Electric vehicles may use electric machines instead of, or in addition to, the internal combustion engine. 
Example electric vehicles include hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), fuel cell vehicles, and battery electric vehicles (BEVs).  A powertrain of an electric vehicle is typically equipped with a battery pack having battery cells that store electrical power for powering the electric machine.  The battery cells may be charged prior to use.  The battery cells may be recharged during a drive by regeneration braking or an internal combustion engine. 
Predicting energy consumption for the electric vehicle is useful to, for example, estimate a distance to empty for the electric vehicle.  Some vehicles predict energy usage based, exclusively, on an average of energy used for certain periods, such as the last five, fifteen, or thirty miles driven; or five minute, fifteen minute, or one hour driving period.  The customer may select between these miles driven and driving periods.