Chibimagic's Weblog

Posts Tagged ‘battery

I decided to get an external battery pack for my iPhone recently. I didn’t know which capacity of battery to get, so I started researching prices, capacities, and efficiencies.

The main thing you need to know is that external batteries have an efficiency of 65-70% when charging off them. iPhone batteries range from 1150 – 1440 mAh. So you need about 2200 mAh of external battery for each full iPhone charge.

I got a Griffin USB Reserve Power, which has 950 mAh and claims to charge an iPhone 3GS (1219 mAh) to 50%, giving 64% efficiency. Thus I can expect it to charge my iPhone 5 (1440 mAh) to 42%, which it hits on the nose.

This PhoneSuit Elite Battery Case has a 2100 mAh battery and claims to charge the iPhone 4 (1420 mAh) and iPhone 4S (1432 mAh) to 100%, which would give it 67-68% efficiency.

The Just Mobile Gum is 2200 mAh and claims to charge your iPhone to 90%. Assuming an iPhone 5, that’s 59% efficiency.

And finally, the Mophie Juice Pack Boost is 2000 mAh and claims to charge your iPhone to 100%. Assuming an iPhone 4, that’s 71% efficiency.

In summary:

  • 65 – 70% typical efficiency
  • ~2200 mAh in external battery for each full iPhone charge

iPhone internal battery capacities:

  • iPhone: 1400 mAh
  • iPhone 3G: 1150 mAh
  • iPhone 3GS: 1250 mAh
  • iPhone 4: 1420 mAh
  • iPhone 4S: 1432 mAh
  • iPhone 5: 1440 mAh
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