Extend your battery life with Juice Defender for Android

While there are a number of battery saving apps around, I found most of them have a minimal effect at best simply because they dont have enough control to really dig into the system and turn things on or off that can really add up to a big difference. Once I tried out Juice Defender it was clear that this was an app that could make a significant impact on battery performance.

How does it work?

In order for an application to extended your battery life it needs to be able to disable battery killing features of the phone, while at the same time not limiting the functionality of the phone so much as to have a negative impact on how the device functions. The top battery drainers are usually:

  • The display itself
  • GPS
  • WiFi
  • 3G Data
  • Cell Standby
  • Voice calls
  • Specific applications (playing a game for example)

Let’s take a look at how some of these features can be tuned for maximum battery life.


Since the display is a pretty big battery hog, the more it is off, the better. Setting a very short screen timeout can help as well as dimming the display to the lowest possible setting that is usable for you is also a good option. Obviously playing games, doing email, and browsing the web are a little hard to do with the screen off so there is a limit as to how much you can really cut down on screen usage.


Unless you really need the GPS running all the time leaving it off is certainly going to be a battery savings although unless you have apps that are accessing it the power drain isn’t really excessive. If you have an app installed like Where’s My Droid you will need to keep the GPS enabled in order to get the location of the device when needed.


Having the WiFi enabled is obviously going to be a drain as it is yet another data connection going and even if you aren’t connected to a WiFi access point, the system will be constantly scanning for available access points. If you have really bad 3G signal indoors and rely of WiFi for connectivity then limiting how often the data services are on and making sure the WiFi system is disabled when not near the access point can make a big difference.

3G Data Services

This one is really tricky because if you disable both WiFi and 3G Data you will not be able to receive emails or instant messages (SMS texts work over GSM so those will still be received). Unless you are a serious connectivity freak and need to respond to messages instantly then you can probably get by with limiting how often the data services are enabled. I currently have mine on for 1 minute every 5 minutes and I don’t really notice a difference. The default setting with Juice Defender is 5 minutes every 15 minutes but I felt that was a bit long when it comes to instant messaging response.

Cell Standby / Voice Calls

There really isn’t anything you can do about the Cell Standby usage but it is one of the lowest drains on the system and a device with nothing else running it on can generally go for days per charge if only used as a cell phone.

How Does Juice Defender Help?

Looking at the screen show below you can see that Juice Defender is just loaded with options. The scheduling feature allows me to not run the data services constantly and even disables them completely during the night (granted, it is plugged in for charging overnight but this keeps me from hearing email alerts all night long so it serves multiple purposes). The system will also disable data and WiFi services if the battery gets below 20% of power, thus preserving phone functionality as a priority.

Since I often listen to Pandora while bike riding, having the data service turn off could often result in not getting the next song for several minutes. By listing Pandora and other network-specific applications to the whitelist, the data connection will stay active while those apps are running to help ensure proper functionality although that will have a negative effect on battery life.

I also use the option to enable the data while the screen is active since I would normally be doing things like checking email or instant messaging.

How well does it work?

The amount of increased battery time you will have is highly dependant on your type of usage. Since I work from home I don’t spend much time on the phone but will use it for email, texting, some instant messaging, and I use the camera on a daily basis and update some WordPress-based sites, get on Facebook, and some occasional web surfing.

Over the past week, Juice Defender has reported an average of a 2x improvement. The question is always going to be how accurate is this and without spending a lot of time graphing, plotting, and trying to do a really scientific study, the best I can do is talk about my anecdotal experience with it. Before using Juice Defender I would take the phone off the charger at around 6:30am and would start getting low battery messages (less than 20% left) around 3-4pm. With Juice Defender I typically don’t need to put it back on the charger until I am going to bed at around 11pm unless I have higher than normal activity that day in which case I may need to stick it on the charger a few hours earlier.

Will Juice Defender Work For You?

Of course it really depends, if you are a light to medium user, yes, it will probably make a nice difference. On the other hand if you drive around all day using the GPS (with the screen on) while listening to Pandora, no, it probably won’t make much of a difference because it won’t be able to turn off any big battery hogging services.

Which Version Should I Get?

There is a free version and a paid version and while I suggest the pay version since I think it is well worth the $3 (give or take depending on exchange rates) you should try out the free version first and see if it gives you any battery savings at all. With the free version I was consistently getting a 1.86x improvement and thought I might be able to squeeze some more out with some of the advanced settings in the paid version. Sure enough, I was able to fine tune it for my needs and bump up over the 2x mark.

How Do I Get It?

Rate & download: Juice Defender

  • http://bGoog.com Jones

    Juice Defender looks sweet. You can also use http://bGoog.com to squeeze more life out of your phone when searching. It uses a black Google which saves battery and it reduces bandwidth usage too!

  • Scott

    I’ve tested juicedefender. With an unrooted phone the app worked quite well for me. Extended it about 2 to 4 hours with moderate use and much longer when the phone sits inactive as the data control is a huge battery saver.
    With a rooted phone, the results are a bit different. I decided to time a 2 hour span first using the app and then disabling it. The two time frames were controlled to be exactly the same down to screen on time. The first 90 minutes (phone just sitting screen off) showed with it on the battery was at 95% while with the app off it was at 98%. I proceeded to Wi-Fi tether for 25 minutes and the results showed with JD enabled power was at 86%; while disabled power was at 91%. The phone was left to sit for another 15 minutes with no use and the screen off the final results were as follows:
    With JuiceDefender
    Without JuiceDefender
    I hope this helps some people when deciding to buy this application.

    HTC Incredible
    UnRevoked root
    Redemption 2.2 ROM
    Hydra Kernel Overclocked Undervolted 1.113GHz v1.0

  • Digitek

    Juice defender works great. Only flaw I noticed that it tends to disable my personalized ring tones and other alerts. Sets them to defaults and sometimes even takes my custom ones out of the list. The app did however extend battery life about 4 hours.

  • Keyra

    Black Google Blackl with juicedefender rocks. juicedefender takes care of most of battery usage. Dark Google http://www.blackl.com does the rest for internet browsing. Also use a black background on home screen.

  • http://www.itpiraten.se ITPiraten

    I’ve been running some tests with Juice Defender too, and I came to the same results. I’m actually saving more “Juice” not using Juice at all.

    Quite honestly, if you are into saving power on your phone, there shouldn’t be too difficult to streamline the usage of data and screen settings.

    Personally I’m not using a “defender” of any sorts, but make it a way of life to check that WiFi and mobile data is off before I head to bed. Often I simply turn on the data connection for downloading/checking mail and other updates, then I turn it off.

    This proves to be the best way to conserve power on the phone. It’s all up to willpower and to not forget the friend in your pocket. (I mean the phone, dudes).

  • Georgi

    DataOnDemand simply turns off data (not wifi or bluetooth) automatically when the screen is off. My battery lasts for 3 or 4 days when I don’t use any data, and at least 2 under my normal use (not huge).

  • http://none tomorthway

    hi i orded juice defender 2 times the ultimate one but its not on my cell phone only the free one i don’t want to be charged twice what should i do? thank you very much yumyumth@gmail.com

  • http://www.basiswissen-derivate.de/ Raymundo Medearis

    What would be your next topic next week on your blog.-.`;~

  • faiq

    what is best setting for juice defender latest version? today…please help me…