MyWARN uses location services to make sure that you receive severe weather alerts based on your present location. At the same time, MyWARN works very hard (along with Apple) to minimize the impact on your battery life.
There are 2 types of location services used by the iPhone
1. Core Location
- GPS: High level of accuracy. High battery impact.
- Wifi: High level of accuracy. High battery impact.
2. Significant Location Update
- Only updates when device changes cell towers.
- Much lower level of accuracy. Low battery impact.
Apple has recently made changes in regards to how the location services icon is used on the iPhone.
Many mistakenly believe that the icon displayed at the top of their screen is a GPS icon. That icon is not the GPS icon, but the Location services icon. This means that some app on the device is using location services. Apps specify the desired level of accuracy, and iOS will use the different tools at its disposal accordingly. (GPS, WiFi, GSM…)
Prior to iOS 6, Apple did not show the location services icon when significant location was being used, only when the GPS or Wifi was being used for Core Location services. With iOS 6, the needle icon (circled in yellow in the top right corner of the image below) shows any time any type of location service is being used, including the low battery usage Significant Location Update service.
When MyWARN is running in the FOREGROUND, the app determines which location service is to be used based on whether you are in an active severe weather alert and on the Precision setting you have set in the app:
When MyWARN is in memory, but in the BACKGROUND or the display is asleep, it ONLY uses the Significant Location Change service. This allows the application to be notified whenever the device changes cell towers. At that point the MyWARN application will update the alerts server with your new location. This has very little impact on battery.
This table shows how often MyWARN updates your location in the alerts server when the app is in the FOREGROUND. This is for Alerts in Motion.
So, the important things to know about MyWARN’s battery life is that when the app is in the background, the only time MyWARN uses any battery is when you change cell towers.
When you have MyWARN in memory, the arrow on next to the location services setting under privacy turns purple. When you have it out of memory, it turns gray. So, you can go to the settings to see current status for each app.
MyWARN will work just fine in the background, your location just won’t be updated as often. If you want accuracy down to 100 meters while driving, keep the dashboard for MyWARN open and don’t let the display go to sleep. But be aware that it will use more battery while you do this, and you might want to keep it plugged in.
Get MyWARN now from the iTunes Store and the Google Play Store