If the Bluetooth is turned on does the iPhone constantly search for a signal and drain the battery in standby?
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Other Does leaving Bluetooth on constantly even if you’re not using it significantly drain the battery?
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While its active but not in use, yes, it's listening for a Bluetooth signal, but that uses a miniscule amount of power. Insignificant.
It does use a lot of power when connected to an active Bluetooth device.
It does use a lot of power when connected to an active Bluetooth device.
My bluetooth is on all the time so I dont have to keep toggling it on/off when I get in and out my car or use my AirPods and it makes no difference at all
Bluetooth 2 uses very little power when connected to a device. An iPhone can run for a full week while connected to BT2 before the battery would drain ( if the BT2 was the only source ). Standby uses significantly less power.
I use a lot of Bluetooth devices/ smart switches and voltage displays for remote voltmeters or thermometers, and when those things are active and the app is the active one, battery drain is noticeably faster than when not using them. The battery drains faster than when watching a YouTube video. But my app updates very fast, so undoubtedly the BT transmitter is getting used a lot.
Unless for some reason it is trying to connect to a device and can't get there.
Also, there are stories about BT being used to send data to apps (as in stealing your information). After going to 13 I had a bunch of apps ask if using BT was OK - I answered no to all since I had read about the data stealing
Also, there are stories about BT being used to send data to apps (as in stealing your information). After going to 13 I had a bunch of apps ask if using BT was OK - I answered no to all since I had read about the data stealing
Yeah, kind of makes you more self aware. It’s another form of location tracking.
Bluetooth in modern smartphones is Low Energy, ever since BT4.2, I have never worried about leaving it on to be honest, it really doesn’t affect battery life, if it does it’s an insignificant amount maybe 0.01% less battery.
Depends on the specific iPhone
Keep in mind, bluetooth is always in use on the iPhone (and other smartphones). If you sniff for bluetooth you'll find the iPhone polling the area. Apple uses bluetooth for many features and functions such as AirDrop, Handoff for the HomePod, Instant Hotspot, Find My.., Siri suggestions, etc etc...
This is a screen shot from my iPad using a Bluetooth LE scanner. I live in a condo so many of these devices aren't mine.
![IMG_8E0D77CF3168-1.png]( "IMG_8E0D77CF3168-1.png")
(click image)
There are even situation that BT is saving you energy. A notable example would be significant location change data without using the actual GPS receiver. As a method to converse energy the iPhone can use data of other devices the BT sees or connects to as an indicator that the iPhones location has changed. Once that is determined apps and features that need general location data can utilize the GPS if needed. BT saved energy because the GPS wasn't activated just to "check" location, it was activated because the iPhone knew there was a location change from BT data.
When BT is actively doing something such as streaming music the processing of app data and screen usage will have MUCH higher energy usage then the BT radio.
If you need a real world example though, consider the Apple Watch. I can go about 2 days with my AW before its battery dies. In that time I'm receiving/responding to text, checking the weather, heart rate, its vibrating when I get a phone calls, change music via the on screen player, using HomeKit and Hey Siri etc etc etc. That is done via a persistent BT connection to the iPhone. So 2 days ~48 hours of constant bluetooth use with a battery that is ~10x (average) smaller then the battery in your iPhone.
TL;DR , its recommended to leave it on due to Apples heavy use of bluetooth for many features/function and as a method to reduce usage of hardware that is more energy hungry. Actual power usage when its on is virtually impossible to track due to the disparity compared to things that use considerable amounts of power like the screen.
EDIT: Fixed some of the typos and grammar, yeeesh
Keep in mind, bluetooth is always in use on the iPhone (and other smartphones). If you sniff for bluetooth you'll find the iPhone polling the area. Apple uses bluetooth for many features and functions such as AirDrop, Handoff for the HomePod, Instant Hotspot, Find My.., Siri suggestions, etc etc...
This is a screen shot from my iPad using a Bluetooth LE scanner. I live in a condo so many of these devices aren't mine.
(click image)
There are even situation that BT is saving you energy. A notable example would be significant location change data without using the actual GPS receiver. As a method to converse energy the iPhone can use data of other devices the BT sees or connects to as an indicator that the iPhones location has changed. Once that is determined apps and features that need general location data can utilize the GPS if needed. BT saved energy because the GPS wasn't activated just to "check" location, it was activated because the iPhone knew there was a location change from BT data.
When BT is actively doing something such as streaming music the processing of app data and screen usage will have MUCH higher energy usage then the BT radio.
If you need a real world example though, consider the Apple Watch. I can go about 2 days with my AW before its battery dies. In that time I'm receiving/responding to text, checking the weather, heart rate, its vibrating when I get a phone calls, change music via the on screen player, using HomeKit and Hey Siri etc etc etc. That is done via a persistent BT connection to the iPhone. So 2 days ~48 hours of constant bluetooth use with a battery that is ~10x (average) smaller then the battery in your iPhone.
TL;DR , its recommended to leave it on due to Apples heavy use of bluetooth for many features/function and as a method to reduce usage of hardware that is more energy hungry. Actual power usage when its on is virtually impossible to track due to the disparity compared to things that use considerable amounts of power like the screen.
EDIT: Fixed some of the typos and grammar, yeeesh
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Thanks for the response everyone! I’ll just leave it on permanently from now on and not worry about battery life since the drain is minimal.
Thanks for asking this question. I’ve always wondered the same thing.
I appreciate those who posted reply’s as well.
I used to worry about this sort of thing, but now I just leave everything on 24/7 so that it works when I need it to without having to intervene. Power management is so sophisticated these days that I don’t think the user needs to concern themselves with micro-management.
I think the Bluetooth tech in latest hardware is called Bluetooth 5.0 LE (low energy), so as the name says I presume it doesn't consume much energy. Its also probably why apple never gave the toggle in iOS to completely turn it off in control centre. It only disconnects for a certain period of time.
For whatever reason this reminds me of my early Droid cellphone days ... Droid 1, HTC Thunderbolt... disabling bluetooth had a noticeable difference in battery life. I think my iPhone 4s was the first phone it really didn't matter on (that I had). I imagine one can't even tell the difference nowadays.
I turn my Bluetooth off when done. IMO, every little bit of savings in battery usage adds up. But that could be just me.
I turn it off when I'm not using it. Not just hit the control center button either, but go into settings and tick it off.
I feel like leaving it on will force my device to keep trying to connect to my Apple watch and car. I do the same for Wi-Fi.
I feel like leaving it on will force my device to keep trying to connect to my Apple watch and car. I do the same for Wi-Fi.
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connecting to different Bluetooth specifications will show a slight increase of power consumption but it’s way overblown and by designhas always used LESS energy than Wi-Fi.
Bluetooth will searchfor longer period of time - a full 30seconds I believe vs Wi-Fi 10 seconds for an available device. That said once connected, due to the bandwidth used by each Bluetooth isfar less power hungry than Wi-Fi in any variance spec.
when you use a Bluetooth 4 device with 2.0 spec compatibility then sure it’ll use more power than say Bluetooth 4-4 devices.
I’ve heard so much crap that Bluetooth uses more power in a smartphone than Wi-Fi yet nobody will ever back it up with facts. Me I’ll point to both governing bodies for each spec for my proof.
I have a Bluetooth (BLE 4.0) wireless battery voltage sensor I got that's used to wirelessly transmit the voltage of a battery (car battery, solar charge bank, etc) to an iPhone.
The specs on that thing are: 0.2mA while in standby and advertising, and 0.6mA while transmitting.
Extremely low power draw.
The specs on that thing are: 0.2mA while in standby and advertising, and 0.6mA while transmitting.
Extremely low power draw.