Alt. Voltage

[Kevin Ryder]

Can anyone tell me the standard voltage for my 2010 5.3 Sierra SLE Crew Cab Z71? Got a "New" Batt. 5 mos. ago and it's near junk already, wonderin if my Alt. is overcharging. When static volts is 11.9, my Alt. is at 14.7, then goes down from there, after 10-12 min.(then turnin the engine off) the static voltage is about 12.9 V, is it too high, or is it just a ****** Batt.? 

[richard wysong]

Sounds normal, a fully charged battery should be 12.6 v but may show a higher voltage for a short time after being charged. Possibly a parasitic drain? If not then you got a bum battery. You put new in quotes, was it NEW or used? If new it's should be covered 100% under warranty

[CamGTP]

I agree, sounds like the truck is charging the battery just fine and the voltage after you shut it off is normal. It will take a few minutes for the voltage to drop and level out after you shut a vehicle off.