iPhone power burst when connected to MacBook?

[Khqai]

Hey,

I've been hovering and reading through these forums since last year and I haven't encountered a problem with my iPhone till now.

Yesterday, my iPhone showed the dead battery image, and I got my cable to recharge it via my MacBook Pro. My MBP was on full battery since morning and it was about 4pm when I plugged my phone in.

I pulled off the charger for my MBP just before I plugged in my iPhone so I could calibrate my MBP battery. After that, the iPhone lighted up and showed the battery to be more than half charged. It was almost dead just a few seconds ago.

Any idea how this happened? Should I be worried?

 

[skoops]

Hey,

I've been hovering and reading through these forums since last year and I haven't encountered a problem with my iPhone till now.

Yesterday, my iPhone showed the dead battery image, and I got my cable to recharge it via my MacBook Pro. My MBP was on full battery since morning and it was about 4pm when I plugged my phone in.

I pulled off the charger for my MBP just before I plugged in my iPhone so I could calibrate my MBP battery. After that, the iPhone lighted up and showed the battery to be more than half charged. It was almost dead just a few seconds ago.

Any idea how this happened? Should I be worried?

Sometimes the iphone battery needs some calibration too... Mine used to switch off and show the "empty battery" with the plug symbol, and when I let it rest for an hour or so with this "supposedly empty" battery it would still turn on after that and continue to work for up to an hour before showing the dead batt symbol again.
Try to discharge your iphone battery as deep as you can... when its almost empty press the buttons every few minutes so it will still light up the lcd to display the "please charge" screen... After a good nights rest or so connect it to (preferrably) the wall charger and let it charge until its FULL (glowing batt icon for at least 1 hour)

this should recalibrate your battery to the extend that you won't get a power-burst from 5% to 40% just by connecting the iphone to a usb port.

Also battery life will be slightly better