<p>We consider the effective theory of heterotic strings in two spacetime dimensions, in a double field theory-inspired formalism, manifestly consistent with <i>T</i>-duality in string theory. Restricting the gauge group to a single U(1), we study the charged black hole solution and perform a precise analysis of the properties of the dual geometry with the O(1, 2; <i>ℝ</i>)-valued generalized metric. We comment on some aspects related to singularities and gauge dependence. We show that the classification program for higher-derivative corrections can also be applied to the heterotic case. We further elucidate how a previously proposed solution to the equations of motion, parametrized in a manner fully non-perturbative in <i>α</i>^′, can be extended to the scenario with <i>r</i> abelian fields and the corresponding O(1, 1 + <i>r</i>; <i>ℝ</i>) symmetry. We discuss some novel features of the solution for charged black holes.</p>