I just basically want to add about 20 and sometimes 80 Proximity Alerts with no time expiration with a radius of around 500 meters. Just wondering whether by doing this will suck up the battery real quick? also would it make any difference by reducing the radius?
This will definitely eat your battery real quick. You never want to be setting more than a couple of proximity alerts in any case, the use-case you describe isn't really catered for in Proximity Alerts.
Proximity Alerts should switch between GPS and Network as required, but in my experience they tend to stick to GPS whenever it's available, and your battery will suffer as a result.
A better alternative would be to use an Alarm and a Service to check your current location against your set of 20 to 80 locations as required. This will let you manage the LBS you want to use (GPS or Cell ID), as well as the frequency of checks, all in one place. Doing it this way will let you manage your battery use much more effectively.
来源：https://stackoverflow.com/questions/1113606/does-anyone-know-whether-the-android-addproximityalert-on-the-locationmanager-is