The phone’s not always using true GPS (reading satellites.) When it does, it uses more energy. In a difficult environment it scans for more satellites than usua

The phone’s not always using true GPS (reading satellites.) When it does, it uses more energy. In a difficult environment it scans for more satellites than usual, which uses even more energy. Basically, the phone’s battery life depends on disabling hardware components, or running them in a low power mode, as much as possible.