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, ready to go.

License: Florida Department of Health MT3608 / 2018. License: Washington Department of Health LF 60618432 / 2017. Attended National University, Graduated 2008.