Solvent-free polymer electrolyte blends of the amphiphilic polyethoxide (I) and the polytetrahydrofuran copolymer (II) with LiClO4 or LiClO4/LiBF4 mixture have been prepared. In II A is either CH2 (IIC1) or CH2C(CH2)CH2 (IID4), dc measurements using Li electrodes on the cells (Li| I/II-Li salt|Li) demonstrate a ‘self-tracking’ process over ca. 24h during which time conductivities increase from ca. 10−6 to 10−3 Scm−1 at 25 and 30°C. The dc results are supported by ac impedance measurements using indium tin oxide (ITO) electrodes in which the complexes undergo transitions at ca. 90°C to give a conductivity after cooling of 6×10−4 Scm−1 at 20°C with low temperature dependence. Structural analysis and molecular dynamics modelling indicate that the cations occupy unimpeded helices of I and anions are located in the interhelical spaces. Mechanisms of ‘tracking’ involving shear-induced orientation of polymer I by polymer II and the redistribution of ions between I and II following imposition of the field are proposed.