2014 Prius Won't Start

they should never have said the hybrid battery was going out. all the lights come on when you first start the car, that's a self check. anything you notice while driving is just a reflection of the unlit icons.
the only way they could know that the hybrid battery was going out would be if a light came on and stayed on.
in that case, a proper code reader would tell them what modules in the battery were defective.
so i think you're good with the hybrid battery, and i have no idea what he meant when saying 'it might have been low from sitting'.
as for the 12v, they must have charged it up, and it held a charge. but i would be prepared for it to fail in the near future.
it would be advisable to purchase a simple jump pack. good to have for emergencies anyway.

 

The maplight will come on when you open the hatch but it will go off automatically. It is possible for the hatch not to be closed 100%. In this case the hatch light WILL stay on but the maplights turn off automatically as do the headlights.

Now, there are ways to drain your battery. One way is to manually turn on the maplight and forget to turn it off. Another is to turn on the headlights after you have turned off the car.

The operators manual is your friend. It will tell you these things and you will learn about features you did not know you had.



Finally, and again, you have to drive the car at least weekly to keep the 12v battery and various other functions in top condition.

 

If the 12v battery was low, you'll get warning for the hybrid battery.
When you press the start button, the checks to make sure everything on the 12v side is
working correctly, then it turns on the hybrid system. If the 12v battery is low, the 12v
systems can completely boot up and you'll get errors because the hybrid can't be started.

After a while, you'll be another Prius expert! Just like all the rest on here!