Bluetooth and GPS battery drain?

[emad1995]

Does leaving blootooth and GPS and NFC on all the time really drain that much battry?

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[B. Diddy]

Welcome to Android Central! I don't have any hard data on this, but my understanding is that Bluetooth and NFC don't use much battery, while GPS can. Unless you need precise location determination at all times, I'd keep GPS off and keep your Location Settings to Battery Saving (which utilizes Wi-Fi and cell towers to estimate your location).

 

[meyerweb#CB]

BT is pretty low power, but if it's on constantly it will periodically check for a signal. I wouldn't worry too much about it, though.

The NFC radio, unless you've hacked the system, is only turned on when the screen is on and the phone unlocked. So it uses no power while the phone is in your pocket. Even when on, it's pretty minimal. But unless you use it a lot, there's a toggle that makes turning it on and off easy. I generally leave mine off simply because I almost never use it.

GPS is a slightly more complex situation. When the GPS radio is in use, it uses a lot of power. But in Android 4.0 and higher, turning GPS on with the Toggle doesn't actually turn the radio on. It simply allows applications to turn the GPS radio on when needed. For example, if you have GPS toggled off, and try to use navigation, it will prompt you to manually turn on GPS, which I find kind of annoying.

Adjusting the location reporting functions and app settings to avoid frequent use of the GPS will give you the convenience of not having to frequently turn it on and off manually, and decent battery life. For more info, see the link in my sig, which has a link to my thread on battery life.

 

[GSDer]

For more info, see the link in my sig, which has a link to my thread on battery life.

GSDer reminds Meyer that his sig isn't visible in the Tapatalk app

Sent from my rooted, debloated, deodexed Sinclair ZX-80 running CM -0.001 using Tapatalk Pro

 

[JudH]

GPS is a slightly more complex situation. When the GPS radio is in use, it uses a lot of power. But in Android 4.0 and higher, turning GPS on with the Toggle doesn't actually turn the radio on. It simply allows applications to turn the GPS radio on when needed.

Well... I've got one GPS app that reports the time it takes to achieve a GPS fix. When I leave GPS on that's very short. When it's been off for days that fix time is several times longer. Even if the AGPS update (uses tower info to update the satellite map) is fairly recent. The only way I can explain that is if the GPS does wake up periodically to update the satellite location map even without an app requesting it. But in any case it does seem to use a lot less power than in the pre 4.0 days. I still like to leave it, and the other location options, off--I don't want anyone knowing exactly where I'm at.

 

[steve_ma]

I started leaving my GPS on all the time a couple of months ago and I didn't notice any real change in my battery life, so I believe your comments about the GPS being application dependent. I still always toggling my BT and my WiFi and I'm wondering if I should just be leaving them on all the time. Or at least leaving the BT on.

 

[meyerweb#CB]

GSDer reminds Meyer that his sig isn't visible in the Tapatalk app

Dang. Another reason I don't like Tapatalk. Anyway, here's the link I was referring to: http://forums.androidcentral.com/sa...ing-you-wanted-know-about-your-galaxy-s3.html

And here's a direct link to the Battery Life thread: http://forums.androidcentral.com/samsung-galaxy-s3/278622-battery-life-tips-myths.html

 

[meyerweb#CB]

Well... I've got one GPS app that reports the time it takes to achieve a GPS fix. When I leave GPS on that's very short. When it's been off for days that fix time is several times longer. Even if the AGPS update (uses tower info to update the satellite map) is fairly recent. The only way I can explain that is if the GPS does wake up periodically to update the satellite location map even without an app requesting it. But in any case it does seem to use a lot less power than in the pre 4.0 days. I still like to leave it, and the other location options, off--I don't want anyone knowing exactly where I'm at.

I'm not sure that GPS wakes up "even without an app requesting it." But unless you carefully and thoroughly configure Android's location settings, and configure every app that may use location settings, the GPS radio will be requested by the system periodically. And some app (Facebook, I'm looking at you) will check your location even if you tell them not to.

I started leaving my GPS on all the time a couple of months ago and I didn't notice any real change in my battery life, so I believe your comments about the GPS being application dependent. I still always toggling my BT and my WiFi and I'm wondering if I should just be leaving them on all the time. Or at least leaving the BT on.

Leaving WiFi on all the time, even when not connected to a WiFi access point, will definitely drain your battery faster. In some informal tests I've done driving home from work, I've seen twice the drain with WiFi on (but not connected to anything) than with it off, during a 1 hr. commute. I recently discovered this app, and find it works very well to automatically shut off WiFi when you leave known connections and reconnect when you get to a known connection:

https://forums.androidcentral.com/e...id=org.cprados.wificellmanager&token=ioEMRJ-0

 

[emad1995]

I just switched from LTE to gsm (it is painfully slow) and my battery has gotten better. I also turned off the google Google backup thing. So far so good

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