A method and apparatus for upgrading in-service or legacy telecommunications cabinets that improves power, cooling, space and EMI capabilities, allowing the cabinet to house updated, telecommunications equipment. The upgrade modules include an extension collar that replaces legacy doors, allowing the attachment of replacement doors having integral heat exchanger units. The extension collar also has support for Electro-magnetic Interference (EMI) shielding gaskets so provide EMI shielding capable of meeting FCC mandated levels. Additional upgrade modules include a battery chamber attached beneath the base of legacy cabinet, cooled and vented by one or more of the heat exchanger doors, thereby providing longer battery life.