Measuring the effects of boron mass addition to V-Fe hydrogen storage alloys on their hydrogen absorbing-desorbing characteristics and loss of boron by hydrogenation by employing new analysis methods; hybrid of Sieverts' method, inert gas fusion method, a

(V0.85Fe0.15)100−xBx alloys (x = 0.5-15 atomic %) were synthesized by arc melting. 5 atomic % addition of boron to alloys markedly increased the hydrogen absorbing reaction rate to 50 times. However, the maximum hydrogen absorbing capacity decreased with the increasing boron addition. Even when it is very difficult to measure the exact amount of desorbed hydrogen by Sieverts' method, a new analysis method “iGFS hybrid method” which combines the inert gas fusion method with the Sieverts' method can estimate approximate amount of usable hydrogen HH/Musable rapidly. With this method, by only 0.5% addition of boron, HH/Musable increased significantly. The nature of hydrogen-alloy system was considered to change from “Compound type” to “Electron flow type” by only 0.5% addition of boron. We have designed a new analysis method “iGFG hybrid method” which combines the inert gas fusion method with the gravimetric method. With this iGFG method, the tendency of increasing boron evaporation by hydrogenation with the increasing boron addition may be observed, although quantitativity is not enough.