Battery Selection - Charger module and step up or step down

Other Hardware Motors, Mechanics, Power and CNC
5

jremington:
Everything you need to know about batteries can be found at Learn About Batteries - Battery University

Pololu has a great selection of voltage step up or down modules.

Wow looks like a great resource of information - it would help me a lot, thanks.

Any idea regarding the common battery selection and modules though ?
would it be better to use step up or step down module
(1 cell vs. 2 cell pack)