Hi bought a second hand key fob programed it and it worked ok, for about 30min then the batteries seem to go flat , i put new ones in it and the same thing happened, has anyone else had this problem? is the key fob dead?

Did a dealer re-prog the fob?

When batt goes you have, remove batt hold down buttons to drain all residual power from fob.

Replace new batt, re-synchronise fob by pressing any of the buttons 3 or 5 time quickly in succession.

Should be in manual