Best 5v and 12v batteries good for high capacity and low cost?

carl1864:
I'm sure a slight variation could be fine. It will be powering things such as arduinos, servos, motors, a camera, etc. Most of which shouldn't be super picky.

Uh, you sure about that? I'm guess they all have a minium require voltage.

carl1864:
Even the camera I'm guessing would still probably run on slightly higher or lower voltage.

That is highly doubtful.