I have my smartphone always plugged in on the charger when using Waze. GPS and mobile data will drain your battery just as fast as playing candy crush or checking out mobile facebook.

I often follow Waze's suggested route, but there were times where I didn't follow the suggested route because it was taking me somewhere else. I ended up getting stuck on the road due to standstill traffic for hours. Other notable times when I did follow it's route over my not so usual route were when it rained hard and flooded the streets a couple of times last year. I got home an hour later than usual but others were stuck on the road for 4-5 hours