Stacked MPPT photovoltaic controller is a product specially developed for photovoltaic energy expansion in base station scenarios. The series connection technical solution consists of PV modules, a stacked MPPT controller, and a DC ammeter; each photovoltaic module is connected in series to the controller. The controller steps down the module output voltage to -48V and connects it to the output busbar of the switching power supply to supply power to DC loads. Designed for communication base stations and similar scenarios, it supports multiple installation methods such as wall-mounted and pole-mounted. Products are divided into two types: Outdoor type and Rack-mount MPPT photovoltaic controllers.