 BOSTON--BUSINESS WIRE--Advent Technologies Holdings, Inc. NASDAQ: ADN Advent, an innovation-driven company in the fuel cell and hydrogen technology space, today announced that it has acquired UltraCell LLC UltraCell, the fuel cell division of Bren-Tronics, Inc. Bren-Tronics. The acquisition closed on February 18, 2021. UltraCell is a leader in lightweight fuel cells for the portable power market with mature products and cutting-edge technology. The portable battery chargers prod 