Battery indicator light
 

Hi there,
When I turn the ignition to "on" before cranking the engine, my check engine light is on, and the battery indicator comes on as well.
Once the car is started, they do not stay lit.
I am taking a road trip next week so I took the car for an oil change and asked them to check the battery. They said it was fine and does not need to be replaced.
However- the battery light is still illuminating when i turn the ignition to "on". (again, not staying lit when they car is started).
Are these people quacks? Is there something wrong that they missed??
thx!