Hydridohelium(1+), specifically , was first detected indirectly in 1925 by T. R. Hogness and E. G. Lunn. They were injecting protons of known energy into a rarefied mixture of hydrogen and helium, in order to study the formation of hydrogen ions like ,  and . They observed that  appeared at the same beam energy (16 eV) as , and its concentration increased with pressure much more than that of the other two ions. From these data, they concluded that the  ions were transferring a proton to molecules that they collided with, including helium.
In 1933, K. Bainbridge used mass spectrometry to compare the masses of the ions  (helium hydride ion) and  (twice-deuterated trihydrogen ion) in order to obtain an accurate measurement of the atomic mass of deuterium relative to that of helium.  Both ions have 3 protons, 2 neutrons, and 2 electrons.  He also compared  (helium deuteride ion) with  (trideuterium ion), both with 3 protons and 3 neutrons.