There are two competing reactions in NiMH cells: Ni(OH){2} + OH- => NiOOH + H{2}O + e- (300mV):: desirable charge reaction 4OH- => O{2} + 2H{2}O + 4e- (-204mV) :: undesirable O2 generation, deep discharge reaction What I remember from chemistry class is the electrons comes with an electromotive force, a voltage, that is needed for each reaction. I suspect the second reaction has a slightly higher voltage requirement BUT I have been too long away from the classroom. Would anyone know how to calculate or lookup the electromotive force needed for each reaction? Thanks, Bob Wilson
