High voltage

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So I got my Yaris hatch last week and so far everything has been great...until a couple of days ago. I noticed that when the car starts and on occasion while I'm driving the battery light flickers a bit. When it happens on startup it'll stay on for a minute or so...if its while I'm driving it'll flicker every now and again. So I started the car today with my mutimeter attached to the battery thinking I must be getting low voltage on startup...quite the contrary. Voltage starts at around 13.5V then spikes up to 17V (right when the bat light comes on) for a little bit the stabilizes right around the 16V mark. Are these cars high voltage? The battery in the car is clearly a 12V. Has anybody encountered this before or can anybody run a meter on theirs and see if its the same as mine? I tried a search but didn't find anything like this.

Thanks