Apr 04 AT 8:00 AM Guest Blogger 14 Comments

JuiceDefender: Save power and extend battery life

Battery life concerns are certainly limiting Android power users and causing us to feel the need to manage our phones more than we should. JuiceDefender aims to remove this burden from the user by monitoring and managing the phone’s power usage for them.

JuiceDefender (JD) works by turning off your power-sucking data connection when you’re not using it. A series of triggers enable and disable your Wi-Fi and APN connections depending on the following: your location (Wi-Fi only), current screen use, battery level, time of day, and a schedule. The triggers are prioritized in the preceding manner. When the application is working as it should, the result is a wonderfully complex but seamless power management solution.

When your phone’s screen is off and you’re not using it, JD turns off your APN connection. But since many applications and widgets rely on background updates, you can set JD to reopen the data connection for 1 minute every 15 minutes (or other user-defined intervals). If the battery level dips below a percentage you defined, JD will turn off the connection, then turn it back on indefinitely when you charge your phone. You can save battery overnight by setting a night schedule that also turns your ringer off.

The best part is that you don’t have to do a thing. Just by installing this application and setting my preferences, my battery life has improved by as much as 1.75x (as displayed by the included widget, which also allows one-touch disabling and enabling of JD). I use my phone a lot during the day, so people who use their phone less will likely see a higher multiple.

The application isn’t perfect, though. The user interface needs dramatic improvement as it is quite intimidating in its current state. All of the controls and settings for each of the aforementioned triggers are on one screen and what each button does is not easily determined. If each trigger had its own individual screen, there would be more room for explanation and less trial-and-error while choosing your settings. If you are confused by the controls, there is an “Easy” button that will set up JD with very reasonable settings.

Occasionally, when you unlock your phone the APN connection isn’t restored. This can be quite frustrating. The developer says that this error isn’t caused by the application itself, but rather an Android bug in which the GSM cell refuses to reactivate the APN connection. Regardless, it’s an issue to be aware of when using the application.


  • Easy way to noticeably improve your battery life
  • Intricate controls allow you to customize your power-saving settings
  • Small widget gives you easy access to on/off controls and tells you how much battery life you’ve gained

Needs improvement:

  • Cramped user interface can be intimidating and confusing
  • APN connection occasionally will refuse to restart when turning on the screen

What’s next?

JuiceDefenders’ developer says he is working on a new user interface and a version of the app in which every trigger is completely customizable. No timetable has been given for the release.

Final Verdict

If you’re interested in dramatically improving your battery life without doing too much manual power management, this application is definitely worth your money. After a few tweaks, this application will become truly essential.

JuiceDefender is available in the Android Market for free. The $3.76 add-on UltimateJuice is required to customize JuiceDefender’s settings. A Nexus One was used to test the application.

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Note: This review was submitted by Mark Cizdziel as part of our app review contest.

Source: Latedroid

From time to time we invite guest bloggers to contribute articles about various Android topics. This is one of those times...

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  • http://gautch.com Gautch

    I’m going to go and say this is a great app, but it rendered my G1 usless. EVERYTHING lagged. I would hit the app drawer, and it would sit…………. then open. Launch any app and sit………….. then open. It took me 35 min just to get into the Market to uninstall it.

  • http://www.gearsoft.mobi GearSoft

    Or you can install the orinal application, WiSyncPlus, which this applications is actively trying to copy. WiSyncPlus has more features and actually works. The interface is crisp, has lots of shortcuts, and is extremely configurable.

  • http://Website justin

    I liked this app & it definitely helped the life of my N1, but it would consistently not reconnect to my APN. Sometimes a reboot would fix it, other times, I would have to go back in and re-input my APN settings. After doing this twice in one evening, I called it quits and uninstalled.

    • http://Website Tebbe

      I had the same problem with my N1. APN would not reconnect or was very slow to connect. Now I only use the app for the location based wifi switching. The APN switching didn’t save much battery life anyhow since the screen uses more power than everything else combined.

  • http://Website Steffen

    Sounds like a great app. but not on market in DK, on my Hero..

  • http://Website Jimmy

    Does anyone have any input on this app vs power manager?

  • http://Website Dave

    Great review of a great app! I look forward to seeing more reviews from you!

  • http://Website Mike

    You really – REALLY – need to note when reviewing future Android apps WHICH Android OS version (v1.5, v1.6, or v2.0) it is programmed for. In this instance, JuiceDefender is ONLY for v1.6 handsets and greater. It is one of my greatest pet peeves, and a tremendous time waster to boot (when I go searching fruitlessly on Android Market), to get excited about an app after reading a good review only to find that it’s not available to ME on my v1.5-based HTC Hero….

  • http://Website Jimmy

    I could be wrong but as far as I can tell your app is just related wifi where his app covers a range of settings. Why don’t you review your app on this site as apposed to flaming this guy.

  • http://Website andros

    nice idea but sofar today ive missed 2 calls because my phone did not come out of sleep in time to start playing the ringtone before the call went to voicemail. im running a N1 on 2.1 and there is 0 excuse for that to happen. ill give it a few more days, but i dont think its going to make the cut.

    p.s. overnight my phone used less than 20% with this thing running. it was a great battery saver, but if it lags for calls, no deal!

  • http://pcmastero.blogspot.com amit sharma

    Although Juice defender is a good Application to save Battery Life of Androids, but what if we can save Android Battery without using any Apps, one should visit this link in order to save Android Battery Life
    Save Battery Life Of Android Phones

  • http://Website Hummingbird

    I tried the free version on my Droid 2. It did not help at all.

  • Pingback: How to make your smartphone battery last all day and more | Firstpost()

  • Allen

    great app