CT21104 is high efficiency DCDC boost converter designed work with Li-Ion batteries. The boost converter is optimized for current load up to 20mA and 3.3V to 15V selectable output voltage ...

The MT3608 is a popular boost converter, able to easily step up DC voltages in useful ranges, at an incredibly low cost. Modules can be sourced from eBay for less than $2, built on a PCB ...