IPhone – How many watts in iPhone LED flashlight

Make sure that the "Automatically install new apps" option under the "Apps" tab when in the iPhone settings in iTunes is UNchecked.

Next, from the "Summary" tab of your iPhone settings in iTunes, check the "Manually manage music and videos".

Finally manually drag/drop the mp3 tracks you wish to add to the iPhone to the open iTunes window when it is focused on your iPhone music. This will directly add the songs without the need to sync the iPhone.

My apologies for not being able to give you a 100% answer. But I did find a informative post about the LED strength of an iPhone 4 (should be the same for the 5 - not the 5S).

Using a combination of direct and reflection lux meter readings, and comparing the same readings to lights of known lumen output, I'd roughly estimate the iPhone 4 LED is about 5 to 10 lumens in normal continuous use.

It briefly gets significantly brighter when used as a camera flash, but it's too brief to measure with my lux meter. I'd estimate it's about 4x brighter, which is around 40 lumens, but only for about 1/4 second.

Source

I hope this helps!