AB5-type metal alloy (LaMm–Ni4.1Al0.3Mn0.4Co0.45) was investigated in alkali metal hydroxide electrolytes (LiOH, NaOH, KOH, RbOH, CsOH) at various temperatures (0–30°C) with no binding materials used. Limited volume electrode approach (LVE) was used in all electrochemical measurements. PCT Sievert’s method was used to determine maximum hydrogen capacity of the alloy to be 4.7at.H/f.u. (289mAh/g). The highest electrochemical hydrogen capacity, nearly reaching the maximum value, was obtained in 6M KOH solution at 30°C (275.1mAh/g) and in mixed 6M LiOH/KOH solution at 30°C (276.1mAh/g). Temperature influence on electrochemical capacity of the alloy was investigated. In the temperature range of 0–30°C the capacity is high and stable in 6M KOH solution and mixed 6M LiOH/KOH and 6M NaOH/KOH solutions. It is possible to improve the capacity of the alloy by designign mixed alkali metal hydroxide solutions.