Patent ID: 8450974

Claim:
A method of extending driving range of an electric vehicle, the electric vehicle including at least a first battery pack and a second battery pack, wherein the first and second battery packs are comprised of different battery types, the method comprising the steps of: a) determining a current state-of-charge (SOC) of the first battery pack; b) comparing said current SOC of the first battery pack with a first preset minimum SOC, wherein if said current SOC of the first battery pack is less than said first preset minimum SOC said method skips to step d), and wherein if said current SOC of the first battery pack is greater than said first preset minimum SOC, vehicle operational power is supplied to the electric vehicle from the first battery pack; c) comparing said current SOC of the first battery pack with a second preset minimum SOC, wherein said second preset minimum SOC is greater than said first preset minimum SOC, wherein if said current SOC of the first battery pack is greater than said second preset minimum SOC said method returns to step a), and wherein if said current SOC of the first battery pack is less than said second preset minimum SOC said method further comprises the step of d) supplying vehicle operational power to the electric vehicle from both the first battery pack and the second battery pack.