2011 Suburban LTZ recently started saying low battery after turning the engine off and leaving in on position I do this all the time so the kids can watch a movie with the engine off but now as soon as it is shut off within less than a minute everything shuts off and it says low battery start engine....battery less than 1 year old had test at Walmart (where I bought it), Orileys and the dealership and all say battery is good. Dealership says no sensor to cause issue.....anyone got any ideas?

 

Welcome from Florida. You should not leave the ignition in the on position when the motor is not running. You should use the accessory position. Try this and see if it helps.

 

That is the accessory position....I have had this Suburban for almost 2 years and it just starated doing this bout a month ago

 

Your post said you leave it in the on position not the accessory position. My truck has both the on and the accessory positions.

 

mine does not have both.....the key does not turn back

 

Not familiar with a 2011, but on the ignition switch, do you pass through accessory position then on, then crank?

 

Mine goes from off-accessory-on-start. It doesn't go back either.

 

Maybe after all that movie watching the battery has had it. Get your battery tested/replaced

 

Yep battery is getting weak.
Vehicle batteries are made for starting the engine only and not running accessories for more than a minute like delayed lighting. That's why they make marine/deep cycle batteries for powering accessories with engine off for extended periods.

 

Actually there is a third choice. An RV battery which is a combination of a start and deep cycle battery.