Shelf designs for battery modules are disclosed. A liquid cooling method for battery thermal management is also introduced using the shelf design. A backup battery system shelf comprises a cooling frame and a thermal conductive pad disposed on one or more surfaces of the shelf. The cooling frame can house a backup battery unit (BBU) or module. The cooling frame is configured to circulate a cooling liquid in and out of the cooling frame. The thermal conductive pad is configured to transfer heat from a BBU module to the cooling frame and liquid circulating within the cooling frame. The BBU module can also include a cooling frame circulating a cooling liquid to transfer heat away from the BBU module.