In　this　paper　we　attempt　to　find　the　electrical　characteristics　of　a　polymer　lithium-ion　battery　with　three　experimental　methods.　First　the　conventional　test,　the　voltages　are　measured　as　the　steady　open-circuit　voltages　after　12-　hour　rest　at　different　state　of　charge;　second　the　rapid　test　for　measurement　of　open　circuit　voltage　during　charge　and　discharge　pulse　with　1　minute　rest;　third　the　constant-current　pulse　test　with　30　minutes　rest　for　parameters　identification　based　on　the　equivalent　circuit　model.　The　paper　also　presents　the　parameters　relating　to　the　electrical　characteristics　for　a　commercial　20Ah　polymer　lithium-ion　battery　including　the　temperature　and　current　effects.