1
vote
2answers
2k views

What is the wattage of my iPhone?

I am trying to make a transportable charger for iPhones, but before I can start this I need to know how much power my iPhone uses when I make an emergency call. If nobody knows this, I will be glad ...
3
votes
3answers
3k views

Can I safely charge an iPhone 4S with a 5V 2A source?

I just bought a New Trent IMP99D external battery, to keep my phone alive while gaming during long-haul flights. It has two USB ports to connect to, one which supplies 1 amp at 5 volts, another which ...
5
votes
3answers
6k views

Which uses more battery when tethering - Wifi or BT on iPhone 4S?

I'm not really bothered which is quicker - I'm guessing this is wifi anyway. I just want to know which would allow me to get the most life out of my iPhone 4S when tethering to it with may MBP. ...