[Q] How much battery does leaving NFC on consume?

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Just got my Nexus S a few hours ago and would like to make use of it's one unique feature: NFC capabilities (with the NFC Task Launcher by krohnjw).

However, using NFC would be much more of a hassle if you had to manually toggle it on every time you were to use it, so my question here is simple:

How much battery is estimated to be consumed if we leave NFC on indefinitely? I'd assume less than leaving BT or GPS on but an estimation by anyone who has any data would be much appreciated.

I can stand maybe 1% extra an hour but anymore than that would be inefficient to the point where it would eliminate any advantages of using NFC at all. I value battery life highly.

None, it has never shown up on the list of what has been using the battery before and I have had this phone since release. I would only imagine it would only use battery whilst in use.

Hope this helps.

Sent from my Nexus S using XDA App

Yep, like GPS only using battery when in use.

That is awesome. Thanks guys.

Originally Posted by Enhanced

Just got my Nexus S a few hours ago and would like to make use of it's one unique feature: NFC capabilities (with the NFC Task Launcher by krohnjw).

However, using NFC would be much more of a hassle if you had to manually toggle it on every time you were to use it, so my question here is simple:

How much battery is estimated to be consumed if we leave NFC on indefinitely? I'd assume less than leaving BT or GPS on but an estimation by anyone who has any data would be much appreciated.

I can stand maybe 1% extra an hour but anymore than that would be inefficient to the point where it would eliminate any advantages of using NFC at all. I value battery life highly.

Almost none, you'll see maybe 1-2% in 10-12 hours difference from what I've tested for an idle nfc radio.

Sent from my Nexus S using XDA Premium App

How does the NFC tag reader know to turn on? GPS is turned on by apps that want to use it. What's turning the NFC reader on and off?

Originally Posted by tatwamasi

How does the NFC tag reader know to turn on? GPS is turned on by apps that want to use it. What's turning the NFC reader on and off?

As almost everything in Android, even teh NFC reader is an app, so it's a background task until a tag is close.

Originally Posted by rentaric

As almost everything in Android, even teh NFC reader is an app, so it's a background task until a tag is close.

The radio still must be active to cause the passive tag to fire though. Fortunately this consumes very little power.

Sent from my Nexus S using XDA Premium App

Originally Posted by krohnjw

The radio still must be active to cause the passive tag to fire though. Fortunately this consumes very little power.

Sent from my Nexus S using XDA Premium App

^^^ This man knows his NFC

I didn't even know gps doesn't consume power when its not "requested". You mean I can turn it on and just forget about it? When I'm not using google maps or iGO it won't consume any battery? Really?