Eutectic Pb Li (lithium 15.6 at.%) alloy has been tested by means of thermogravimetric analysis under different hydrogenation conditions in the temperature range 25-650 degrees C. The melting temperature of the material changes irreversibly after the first heating ramp, from that of the eutectic alloy (240 degrees C) to that of pure lead (330 degrees C). The capacity to upload hydrogen depends on the thermal cycling and on the humidity presence. Particularly, it has observed that the presence of water traces in the environment leads to the formation of lithium hydroxide. This reaction affects dramatically the hydrogen uploading of the Pb -Li. Such a behavior is discussed in details by considering the change of weight of the Pb -Li along hydrogenation and thermal cycling. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.