Shelf design for battery modules

An electronic rack, comprising:

• a plurality of server blades, each server blade including one or more servers to provide data processing services;
• a power supply unit coupled to the server blades to provide power to the server blades;
• and
• a backup battery unit (BBU) shelf to provide backup power to the sever blades when the power supply unit is unavailable, wherein the BBU shelf including
• a housing operating as a cooling frame, the cooling frame including an outer container and an inner container enclosed by the outer container, wherein the inner container includes one or more slots to receive one or more backup battery units (BBUs) that can be inserted from a frontend of the housing, each of the BBUs containing one or more battery cells,
• a cooling liquid circulation area defined by a space between the outer container and the inner container to receive and circulate a cooling liquid around the inner container, and
• a thermal conductive pad disposed on one or more interiors surfaces of the inner container configured to transfer heat from at least one of the BBUs to the cooling liquid circulating between the inner container and outer container.