Build a Portable adjustable power supply (built-in battery + external power supply)

This is a portable adjustable power supply, using the SK120X as a digitally controlled buck-boost converter, with an output voltage of 0-36V and an output current of 0-6A It has 4 built-in 21700 batteries, and a switch controls power on/off and power supply mode Part SK120X Digital Control Adjustable DC Buck-Boost Power Supply 21700 Lithium Battery 4-series lithium battery protection board （Overcurrent 10A, the larger the better to reduce heat） Type C buck-boost fast charger 4S Amass XT60E-F (Two pieces) KCD4 Rocker Switch 4MM Banana Plugs (Red and Black, 2 pieces for output) Power Indicator Board (16.8V, connect directly to battery positive and negative) M2x8 Screws（10 pieces, for fixing the charging board and back panel） M4x12 Pan Head Self-Tapping Screws（2 pieces, for fixing the handle） 3D File : https://makerworld.com/en/models/1849570