I bought a used Troy built GTX20 yesterday.When I got it home I cut some heavy grass with it for about 45 minutes.I noticed that the battery light was on.I drove it to my garage and turned it off.When I tried to restart, it was dead.So I put a trickle charge on it over night.I checked the battery this morning and it read 12.76 volts.I started it up and the out put read 12.66.As soon as the electric clutch is engaged it go`s down to 12.33.I am thinking it should be about 13.5 with no load on the engine and maybe 13 with the clutch engaged.Does anybody know what the readings should be??I am also wondering if this unit has a Voltage regulator hidden somewhere?I can not see one.Thanks for your help.OB