Equilibrium charge distributions of lithium ions passing through a carbon foil have been measured in the energy range 1-6 MeV. Average equilibrium charges (q) over bar are found to connect smoothly with previous high energy data above 6 MeV. It was found that the present results of both charge fractions and (q) over bar can be well reproduced by the empirical calculations based on the independent electron model. We also found that available semiempirical formulae for (q) over bar cannot reproduce the present experimental data at all. A new semiempirical formula is presented for Li ions in the energy range 0.8-30 MeV. (C) 1999 Elsevier Science B.V. All rights reserved.