Diamond LED

Project was designed for 18650 battery cell and electronic components listed below.

Charging board:
https://www.aliexpress.com/item/Smart-Electronics-10pcs-lot-5V-Micro-USB-1A-18650-Lithium-Battery-Charging-Board-With-Protection-Charger/32495346046.html?spm=a2g0s.9042311.0.0.27424c4duUE5Dd

Switch:
https://www.aliexpress.com/item/Hot-20pcs-5V-0-3A-Mini-Size-Black-SPDT-Slide-Switch-for-Small-DIY-Power/32807468914.html?spm=a2g0s.12269583.0.0.1d9ac79eOZ8fxF

LED + resistor:
I used 9 RGB Slow Flashing LEDs, connected in parallel + 1.2 ohm, 1W resistor.

https://www.aliexpress.com/item/100pcs-Super-Bright-5mm-Round-Transparent-RGB-Slow-Flash-Light-Emitting-Diode-LED-Diode/32279376708.html?spm=a2g0s.9042311.0.0.27424c4dtarmq8

For other types of diodes you have to use proper value of the current limitting resistor.