Underground Prius racing clubs know that if you string 105 9 volt batteries in series you can acheive 100 mph going downhill with the interior stripped clean and at altitude
The first rule of Prius Fight Club!
http://www.caranddriver.com/roadtests/7701/toyota-prius-page4.html
ACCELERATION Seconds
Zero to 30 mph 3.4
40 mph 5.6
50 mph 8.2
60 mph 11.3
70 mph 15.3
80 mph 20.5
90 mph 27.6
100 mph 39.6
Street start, 5–60 mph 11.3
Top-gear acceleration, 30–50 mph 5.5
50–70 mph 7.9
Standing 1/4-mile 18.3 sec @ 76 mph
Top speed (governor limited) 104 mph