It feels like I’m being trolled now so I’m going to move on from this thread. I know that some (or perhaps just one) of you is now in that typical but unfortunate message-board/internet interaction mode whereby no matter what I say, your response will be designed to disagree.
And other people are just missing the point.
But yet other people are being helpful, so thankyou to those people. To be honest I do feel more inclinded towards leaving my phone plugged in longer than it needs to be, and possibly getting into the habit of plugging it in whenever I can (‘commando refuel’ I think is the name for the strategy??)
It’s a new phone. I tend to be anal about new things for a while… until they stop being new. I was like this with my ipod, but now it just gets thrown about, and charged like ‘normal’ people charge things
As you continue to observe your phone’s charging/discharging, do note that the phone has many different power modes. Your anecdote about 15% (etc.) doesn’t mention whether you were on a call the same number of minutes or used the screen the same number of minutes or were on airplane mode the same number of minutes. While you’re connected to a call, the battery will be draining wayyyy faster. (A no-call day drops my battery by only a few percent, while a day with an hour-long call drops it by maybe 30%.) Also, were you in equivalent coverage both days? The phone can switch into a higher-power mode when the signal is weak, and a lower power mode when the signal is strong. Did you use more 3G data one day? Did you kill 45 minutes at the mechanic’s playing a touch-screen game (using the backlight that whole time)?
This battery technology does degrade with time, and it is possible your battery is ready for replacing. (The lifetime is around 2 years, but excessive heat can shorten that considerably. Do you ever leave the phone in a hot car?)
Toward the original question, here’s my WAG: the battery engineers at Apple believe that users have no reason to let the charge get so low that they would be taken by surprise by a dead battery, so they don’t feel your suggested feature is a priority and/or would fit their intended streamlined UI motif.
