Vehicle telematics unit power management

A system and method(s) for conserving vehicle power when a primary power system of a vehicle is powered down during a voice call. The method includes the steps of: (a) receiving an indication that the vehicle's primary power system is powered down during the voice call; (b) after a predetermined period of time, determining whether to power down a secondary power system associated with a vehicle telematics system; (c) when it is determined that the secondary power system should be powered down, powering down the secondary power system; and (d) when it is determined that the secondary power should not be powered down, waiting the predetermined period of time before again determining whether to power down the secondary power system. The determination of steps (b) and (d) include detecting an absence of voice activity during the predetermined period of time of steps (b) or (d).