Issues after 1st oil change

I also had a drop in MPG from 54.5 to 51.2.
I saw they overfilled my oil and lowered my tire pressure from 42/40 to 32/34.
Hope This helps
As far as the battery etc. I haven't a clue.

 

I've experienced the same thing with my Prius, but I do not worry too much about it. After a few minutes of driving, everything is indicated back to normal with a full charge on the batt. My MPG fluctuates from 46 down to 42 then up again to 45 MPG.

I plan to change my oil at 3K, since this is going to be my first. 2.2K so far on the odo. Enjoy your Prius.

 

I believe the ICE will start but won't show a charge when the battery is in the green, it only starts for the heater, I bet if you shut the heater or A/C control off the ICE would have shut down.

 

You don't say where you're located, but if you are in a place where cold weather started about a month ago, that's likely to be the biggest cause of your mileage reduction. Based on reports from many PriusChat members in colder climates, the mileage can drop significantly when the weather cools off.


That said, checking your tire pressure and oil level is a good idea anyway. There's some debate about how much effect too high an oil level will have, but low tire pressure has a very direct impact on MPG.

 

Yup. Here in Minnesota, my efficiency has dropped all the way down to 44 MPG!

Sadly, that is actually down quite a bit from the low 50's I enjoy during the summer... but still way above most every other vehicle on the road.
.

 

This is what we console ourselves with, too.
The Prius is still getting double the MPG of our other car, even in winter