Used or new? If you don't have the manual, you need it - can get online. Go thru the manual and set up batt by the manual. If its a setting you've got wrong, that should clear it up. Can get manual here -


http://www3.towerhobbies.com/cgi-bin...&I=LXHDJ1&P=ML

If this doesn't fix it and its same for diff batts of diff type - poss charger prob.