Battery Bearer is a uncommon Creature — Human Artificer card from The Brothers' War (BRO), collector number 207. Current market price: $0.14 (foil $0.20), TCGplayer market prices via Scryfall.
Creatures you control have "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell." Whenever you cast an artifact spell with mana value 6 or greater, draw a card.