A power system for a vehicle having a vehicle body and door includes a first battery disposed on the vehicle body, a second, rechargeable battery disposed on the door, a first electrical contact disposed on the vehicle body, and a second electrical contact disposed on the vehicle door. The genes are replaced by a chimeric gene encoding a heterologous entry protein derived from the Vesicular Stomatitis Virus G protein or GP64 of baculovirus. The backup logic creates multiple HDAGs for one or more of a plurality of retention policies and represents directories by a first node containing a payload of metadata and weak references to roots of child nodes, and a second node containing references to the first node and to any HDAGs corresponding to files andor directories governed by an active policy of the plurality of retention policies.