Are there any apps that will specifically help to drain a battery down quickly?

The scenario I would want to have this is if I want to quickly drain the battery so I can charge it fully again. Some say that this will help extend the battery life by fully draining/charging the battery.

  • 3
    Turn on your GPS. Place cell phone near the window. Also change your setting to always keep screen on. Watch battery drain away. :D
    – abhi
    Sep 16, 2010 at 19:16
  • 2
    You shouldn't have to do this as you most likely have a Lithium Ion battery and the process you are talking about is for NiCad batteries. For Li Ion batteries the less you discharge them the better. See Adam Lassek's answer below.
    – Matt
    Sep 29, 2010 at 18:49

5 Answers 5


This question is along these same lines: What causes battery to drain faster than it can charge?

So there may or may not be an app designed to drain the battery but you probably just need to turn on an app that uses the GPS. This will help to fully drain your battery but I don't know that doing so before recharging will extend the battery life.


Do not do this. You are actually harming the lifespan of your battery when fully discharging it before a recharge. See this site for a discussion of how depth of discharge affects battery life.

The only reason you might want to fully discharge before a recharge is if you have a NiCad battery that is susceptible to the memory effect. Your smartphone most likely uses a Lithium-ion polymer battery, so there is no good reason for you to totally discharge your battery. The lifetime is longer if you have a shallow depth of discharge.

  • 1
    Below is cited from this question Batteries with fuel gauge (laptops) should be calibrated by applying a deliberate full discharge once every 30 charges. Running the pack down in the equipment does this. If ignored, the fuel gauge will become increasingly less accurate and in some cases cut off the device prematurely.
    – IsmailS
    Apr 28, 2011 at 7:30

I know that my phone -- HTC's Evo -- actually has a diagnostic tool thats sole purpose is to drain the battery as fast as possible. Open up your dialer and enter:


You don't need to press send or anything. A recent update for the Evo blocked these tools so hopefully you can still access them. You can also look up device specific codes if yours happens to be different. Rooted users have found a way to get these tools back.

The utility turns up brightness all the way, prevents sleep, turns on the camera and flash, turns on the GPS and constantly polls it, etc. Basically everything that can drain the battery but not damage the phone is done (ie it doesn't constantly vibrate because that would probably be bad).


Activating wifi-network sharing should empty the battery in a couple of hours.

After the first couple of charge cycles the battery should be at optimum performance. How this works I don't really know. But after the initial couple of days I had a little more of use out of a fully charged battery.


I found a combination that draws more than 2 Ampere on my phone without requiring any non built-in app.

  • Flashlight!
  • Brightness to the maximum. Obvious yet easily forgotten.
  • Disable adaptive brightness. Sleep after 30 minutes or better: play a video.
  • Picture in picture video streaming (YouTube, Netflix,...) This keeps active: 1. the video decoder, 2. the screen, 3. wifi (or cellular if you can afford it). If you can't use the network try Video Looper, no permissions required. There's also a "loop one" option buried in the options of MX player
  • GPU load like for instance https://jbouny.github.io/fft-ocean/ or https://webglsamples.org/aquarium/aquarium.html Keeps the GPU active with just a web browser; no app needed.
  • GPS Navigation
  • A fan to avoid thermal throttling!

Some apps show the total battery brain.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .