  We present a calculation of the charged pion electric polarizability using
the background field method. To extract the mass-shift induced by the electric
field for the accelerated charged particle we fit the lattice QCD correlators
using correlators derived from an effective model. The methodology outlined in
this study (boundary conditions, fitting procedure, etc.) is designed to ensure
that the results are invariant under gauge transformations of the background
field. We apply the method to four $N_f=2$ dynamical ensembles to extract
$\alpha_{\pi^\pm}$ at pion mass of $315$ MeV.
