Comment by joshspankit

My personal experience with 3 Apple devices:

“30% to 0” and “Pull AC and it instantly dies” are typically a combination of load and device temperature. High CPU/GPU usage, high brightness, 3G/LTE usage, and cold temps and the device doesn’t have a chance.

It’s been somewhat fascinating to monitor power usage in this really crude way. TikTok on iOS, for example, uses so much power that it’s the most likely to cause the device to shut off. FB Messenger is in the top 5. Some of Apple’s background processes will also cause it, as will paging memory to disk.

There’s another bit of information that will not surprise many people on HN: high-amperage charging will cause the battery percentage to be “more wrong”. Devices will report 45% or higher and still die as if they were reporting 30%. Charging at 500mA will not only make it “more correct”, but will typically mean that a device will not suddenly die until it’s in the single digits.

This is still n=1 of course.