Is NFC a battery drain at all?

[Steve686]

Not sure if NFC is a battery drain for those who do not want to use it. I know you can use it even when the screen is locked, and I loved that feature. Makes it absolutely flawless.

I assume it's a very, very low output signal, hence, Near Field...

But, is there also a way to turn it off? And does Airplane Mode turn it off?(Forgot to check this when I did a couple of Pay transactions earlier today.

 

[Intell]

It is only turned on and used when preforming a non-in app Apple Pay transaction. At all other times, it is turned off. Even when on, it uses very little power.

 

[Steve686]

It is only turned on and used when preforming a non-in app Apple Pay transaction. At all other times, it is turned off. Even when on, it uses very little power.

But how is it activated from lock screen, then? There has to be a signal that wakes the NFC radio? But in order to do that, wouldn't the NFC radio already be required to be on/receiving?

I know it uses very little power, I just want to know exactly what activates Apple's particular NFC modes.

 

[Intell]

It's activated by you preforming a transaction with TouchID.

 

[Steve686]

It's activated by you preforming a transaction with TouchID.

Negative.

I held my locked phone up to the NFC reader, and my phone awoke to complete the transaction. THEN, you use the TouchID.

The process somehow is like a handshake wirelessly.

 

[Intell]

Don't forget that NFC is also passive in nature. It will and can receive a wake up signal without needing any power. It will only transmit once a transaction is taking place. All while using such a small amount of power it isn't even worth comprehending.

 

[Steve686]

Don't forget that NFC is also passive in nature. It will and can receive a wake up signal without needing any power. It will only transmit once a transaction is taking place. All while using such a small amount of power it isn't even worth comprehending.

Ya. I was just very curious about the wake up procedure.