system
Given the following post, respond as if you're commenting on Reddit:
human
ElI5: Why do mobile companies insist on fully charging the phone on first use?
gpt
There’s no easy way to measure the charge level of a lithium ion battery, especially at higher charge levels. Battery controllers won’t pick up self discharge that happens over time so charging the device that’s been sitting for a while to full and leaving it on charge for a bit is necessary to recalibrate the device’s measurement of the state of charge.