Does Android ProximityAlert or Geofence drain more battery when the phone is closer to a monitored location?

Question

If I use an Android ProximityAlert with a given radius (say 100m), and my phone is regularly near (or at) that location, will the battery drain be greater than if I am rarely near that location? Is there a distance within which the battery drain increases?

What about with Geofences instead?

Ideally, I'd like to understand the impact on battery life of the following scenarios:

R = radius of the proximityAlert or Geofence area D = distance of phone from location in proximityAlert

• D < R (phone definitely within proximity alert location)
• D >> R (phone definitely outside proximity alert location)
• D ~= R (phone near boundary of proximity alert location)

Is there any particular location (ie value of D or of D-R) where the phone will automatically change location provider to a more expensive option to increase accuracy?

Abuzz

I have two identical test phones, which I'm using to test battery life in different scenarios. Currently, I've set up a location at my home, which means I'm always in the case where D < R, and I'm wondering if that's a meaningful test, or if I'm seeing a worst case scenario. I plan to test it more thoroughly, but it takes time, and I'm hoping that someone else has already done this :-) – Abuzz

I rest my case, its a difficult problem ( I mean the life of phone, the battery life, other apps running) to solve. Crazy. Upvote. – Minacious

Great question. I'd love to hear more from Google about the cost on battery life of registering geo fences. Also does it make a difference if you have 1 fence vs 300 fences? – Roentgenogram

Answer 1

When you go near the geofence , the GPS gets turned on more often to check the users "FINE_LOCATION" and when you are not close to the monitored location the phone uses "COARSE_LOCATION" which uses the cell phone towers and 3g/4g networks to get the phones current location. The "FINE_LOCATION" (needing GPS) will drain more battery than "COARSE_LOCATION".

this is why we need to set both the COARSE_LOCATION and FINE_LOCATIONS in the Android Manifest.

Mandamus

When you said: "When you go near the geofence , the GPS gets turned on" That is not correct. In my testing, the GPS does NOT get turned on by Android when you get close to fences. I know this because,the gps takes a long time to turn on (like up to 60 seconds) and there should be an icon in the status bar indicating that GPS is on. I haven't seen those things in my testing. Also, I've found that Android can be VERY accurate (within 5 meters) with just wifi on, when you get in range to a wifi network. – Roentgenogram

Answer 2

Proximity alert will fire up gps, if it turned off , every after 4 minutes in order to update your location. you may not realize it, but to add something to your tests, add a broadcast receiver to constantly monitor the state of gps, and then test it within a 4 minute span

Hinckley