Abstract: Fuel cells and electrolytic cells can provide energy support for long-term missions and bases in space, but different gravitational levels in space affect their performance, so experimental studies in unconventional gravity environments are necessary for the development and improvement of fuel cells and electrolytic cells for spaceflight. The experimental studies of fuel cells and electrolytic cells in unconventional gravity conditions are reviewed. The analyses and discussions show that the change of gravity level leads to the change of gas-liquid two-phase flow characteristics inside the fuel cell and electrolytic cell, which affects the performance differently. There is still a lack of experimental data on fuel cells in hypergravity and long-term microgravity, as well as unconventional gravity experiments on regenerative fuel cells. Fuel cell and electrolysis cell experiments under unconventional gravity conditions will not only help to promote the intersection of fluid physics and thermophysics with electrochemistry, but will also provide a data basis for the development of regenerative fuel cell systems in space.