The hydrogen storage of bending deformed Ni-functionalized (8, 0) single-walled boron nitride nanotube is investigated by using the state of the art density functional theory calculations. The average adsorption energies per hydrogen molecule -0.478 eV for the undeformed BNNT-?=0 and -0.255,-0.328, -0.288 eV for the deformed BNNT-?=15, 30, 45 nanotubes, respectively meet the DOE target for physisorption (?0.20 to ?0.60 eV). The curvature attributed to the bending angle has affected the average adsorption energies per H2 molecule. With no metal clustering, the system gravimetric capacities are expected to be as large as 6.9 wt%. The hydrogen storage reactions 4H2 + Ni-BNNT-? (?=0, 15, 30, 45) are characterized in terms of density of states, pairwise and non-pairwise additivity, infrared, Raman, electrophilicity, molecular electrostatic potentials and statistical thermodynamics. The free energies and enthalpies meet the ultimate targets of the department of energy for minimal and maximal temperatures and pressures. The closest reactions (with ?=0, 30) to zero free energy exhibit surface coverage values 0.999 and 0.973, respectively. The translational term is found to exact a dominant effect on the total entropy change with temperature, and our calculations expect that complexes (with ?=0, 30) are promising hydrogen storage candidates.