Does the Mophie Juice Pack Boost use the smart battery technology that allows it to use the juice pack first and then use the iPhone battery?

I am looking for a stand/charger that I can use with the iPhone 4 that allows me to play mp3's etc all day long and then in the evening I can take the iPhone out and still have full charge. I believe the Mophie Juice Pack Air has this technology to use the external battery first and then the iPhone battery.

I assume that if this wasn't the case the Boost would just keep charging the iPhone while the battery is depleting? Would this reduce the life of the iPhone battery?

  • Asked by Nick M
  • Oct 18, 2011
mophie Juice Pack Boost External Battery for iPhone and iPod

mophie Juice Pack Boost External Battery for iPhone and iPod

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1 Answer from the Community

  • Answer

    In active use of my 4S (i.e. tethering my Air over wifi and use of Spotify), the phone will charge while the battery pack drains. I think this does exactly what you want. The iPhone's charge circuitry won't let it do weird things to its internal battery, and it definitely supports heavy usage while charging (think of the Juice Pack as exactly the same as Apple's wall charger: it provides the same voltage and supports the same 1A draw as the phone's provided charger).

    • Answered by Christopher B from San Francisco
    • Jan 12, 2012