Which of these folding quad chairs is heated, and how is the heat powered?

Two of the three are heated. The Deluxe Heated and the Heavy-Duty Heated warm both the seat and the back, in zones, with three temperature settings and wiring built to take being folded; the plain Heavy-Duty chair is the same style of chair without the heating. The heat runs on USB: a long cable comes with the chair and plugs into a power bank you carry or a wall adapter if you are sitting near an outlet, and neither of those is in the box. There is no battery inside the chair, so nothing arrives charged and nothing goes flat in storage - and unplugged, a heated chair is still an ordinary folding quad chair, simply without the warmth. For an evening by a fire pit or on the sidelines of a game, a mid-size power bank is plenty; keep it in a coat pocket rather than on frozen ground, because the cold is what shortens its run, not the chair.