"Battery Usage" page irrelevant I have been doing battle with the battery vampires, apparently similar to a lot of people on here. I have a Samsung Droid Charge (SCH-i510), and service with Verizon.

I have noticed my battery life growing shorter and shorter.

As I've had the phone for at least a couple of years now, my very first step in the solution was a new battery. No difference. Even with a brand-new battery, my charge would last less than 24 hours. So, I began my research. Discovered all the settings to correct, and changed them, (wifi, GPS, 4G, etc.). Still, my phone charge would barely last from when I unplugged it in the morning until I plugged it in to charge overnight. I dove deeper into the phone settings. This weekend, I noticed that my phone battery lasted all weekend. ALL WEEKEND ON A SINGLE CHARGE.

As I live in a rural area,  my service is a bit spotty. This got me thinking. I started reading all the permissions that the apps on my phone call for, looking for one that would cause increased battery drainage while in urban areas (around more cell phones, towers and wifi hot spots.) I found one such ambiguous app: "Bluetooth Test". This app is a "default app" and is automatically granted permission to MODIFY BATTERY STATISTICS, (apparently to hide its tracks from the user,) as well as pretty much permission to do whatever it wants, right up to internet access. Apps granted such permissions pretty much makes the Battery Usage page irrelevant, as any app can reassign its battery usage to "Display". As of yet, I've found no mention of it on this site. Does anybody have any info on this app?
The BluetoothTest app is part of the stock image on most Samsung devices. It's a system app, and as the name suggests, it's for testing the Bluetooth hardware. If you root the device, it's safe to remove/"freeze" this app. It shouldn't normally run or cause any problems at all, though some users have reported that in some cases it shows up in the battery usage list for their device. (Googling {Samsung BluetoothTest} gives you some forum posts, but no solid information.)

As for the permission to "modify the battery statistics", this label is wrong (see this old Android bug report), and is phrased differently in newer Android versions. The permission only allows the app to read the battery statistics. An app might use this to help you identify which apps use the most power, or to find and disable power-hungry apps on low battery.

There's no real need for BluetoothTest to use this permission, but as the app info screen explains, many system apps are bound together in a single process, because this is more (power and memory) efficient. As a result, all of the apps bound together in this way share the same permissions, which means the single process has more permissions than any one of the apps needs. This only applies to system (i.e. built-in) apps: apps you download and install are kept separate for security.