A sensitive open-type calorimeter was used to measure excess heat production during electrolysis in Li2SO4/H2O solution with Pt-anode and Pd-Ni thin film cathodes 9000 Å thick, sputtered on Al2O3 substrate. In order to estimate the actual performance and possible measurement errors during electrolysis in the calorimeter used, including heat convection, bubbling and possible H2+O2 recombination,...