Project Specs & Instructions ▼

Pack Specs

• Output Voltage: 7.4V (8.4V max)
• Est. Max Power: 50W+ (load dependent)

Parts List

• (24) 1S 3.7V LiPo (Lithium Polymer) Pouch Cells
• (1) Galaxy Watch 5 Case
• (1) High-Power LED (e.g., CREE XP-L) on PCB
• (1) SPST Momentary Pushbutton (7mm)
• (1) 3-pin JST-XH Balance Connector
• (1) Micro XT30 Power Connector
• Power Wires: 22-24 AWG Silicone
• Balance Wires: 26-28 AWG Silicone
• Transparent TPU/Resin (for band links)
• Purchase Micro 1S LiPo Cells

Build Instructions

1. 3D print transparent band links.
2. Wire two 3.7V cells in series (makes 7.4V block).
3. Embed one 7.4V block per link.
4. Run main power bus (red/black) in parallel to all links.
5. LED: Mount LED on a small heatsink/PCB. Solder leads.
6. Button: Solder leads to momentary pushbutton.
7. Connectors: Wire main bus to XT30. Wire final link's 3.7V tap to the JST balance plug.
8. Final Circuit: Connect Battery (XT30) -> Button -> LED Driver -> LED.