Conductivity and dc polarization studies performed on poly(ethylene oxide) PEO-LiX-KX amorphous electrolytes, containing LiSCN, LiN(CF3SO2)2 (LiTFSI) or Li[CF3SO2N(CH2)3OCH3] (LiMPSA) and their potassium counterparts, yield data–composition relationships that can be fitted by means of classical models assuming ideality. Though this approach is not rigorous, it provides information about the nature and strength of the ion–ion, short-range interactions in the PEO-LiX corresponding systems. At the global concentration chosen for these studies, C∼0.8 mol dm−3 (EO/salt=30), evidence is brought that stronger two-body interactions (ion pairing) take place in the PEO-LiMPSA system than in the PEO-LiSCN system, and these interactions are much stronger than in the PEO-LiTFSI system. Another feature of these three systems lies in their three-body interactions, which appear to mainly consist of LiX2 − triplets. Though their strength is not as great as that of the two-body interactions, it increases in the order LiTFSI<LiMPSA<LiSCN.