… [Keith Chen, Uber’s head of economic research] revealed that Uber knows when the battery on your phone is low — it keeps tabs on your battery so the app knows when to switch into low-power mode — and that it knows you’re willing to pay more for a ride when your battery is running out. . . . “[W]e absolutely don’t use that to kind of, like, push you a higher surge price, but it’s an interesting kind of psychological fact of human behavior,” said Chen.
Source: Uber Knows When Your iPhone Battery Is Dying And You’re Getting Desperate