The paper generalizes a many years' experience in manufacturing and testing of multicell PHOTON stacks based on hydrogen-oxygen alkaline matrix fuel cells. Inter-cell processes effecting the stack lifetime are concerned, the main of which is the current flow between cells along a thin electrolyte film in gas collectors. This process is accompanied by electrolyte redistribution among elements resulting in their polarity reversal, and electrochemical corrosion in metal gas collectors of stacks.