How many hours of audio recording can the iPhone do on a single charge?

He didn't ask how many MB/Hr the voice memo app consumes. He asked how long the battery charge would last.

Only one way to know for sure (because it depends on the condition of the battery, what other apps are running, the brightness of the screen, BlueTooth enabled, etc....) try it out. Charge it up and use as normal and watch the battery status indicator. Come on, you can do it. 😉

Since you know what he wants, why don't you do it then?😀

You do the maths.

Sample rate: 44.100 KHz

Sample size: 16 bit

Channels: mono

Bit rate: 302 kbps

0.56 secs = 2.1 MB

Then roughtly take 1 min. = 3 MB

1 hr = 60 mins = 3 x 60 = 180 MB

Come on you can do it.😉

I'm here to help you out.... which way did you come in? 😉

Seriously though, since it's only meaningful if he does this test on HIS phone, I'll leave it to him.

You're welcome.

Knowing about battery without the iPhone free space capacity is meaningless.

But there're quite a number of portable charger available.