The　stability　of　the　Co-C　and　Pt-C　eutectic　fixed　points　is　investigated　in　this　article.　Six　cells　were　employed　for　the　testing.　Two　existing　cells,　a　Co-C　cell　with　a　C/C　sheet　incorporated　and　a　Pt-C　cell　equipped　with　a　graphite　sleeve　that　had　been　previously　aged,　were　studied　to　determine　the　presence　of　anomalous　drifts　or　degrading　robustness　that　may　possibly　appear　when　the　testing　period　is　extended.　The　stability　of　four　cells　of　a　new　design,　a　Co-C　cell　and　three　Pt-C　cells,　which　were　constructed　in　a　hybrid　manner,　to　include　a　sleeve,　foil　lining,　and　two　of　them　with　a　cavity　support,　were　likewise　tested.　Results　show　that　different　designs　of　Pt-C　cells　can　exhibit　good　stability.　However,　for　Co-C　cells,　the　cavity　rift　remains　a　problem.　The　possible　reasons　for　this　rift　and　methods　for　increasing　cell　life　are　discussed.