DEFY XT: Phone is hot and battery runs down quickly


If you find your DEFY XT running hot and the battery not lasting the entire day, you’re not alone. This usually happens due to one or more scenarios that might be avoided with some attention to the phone’s configuration. Here are the top 3 reasons for this trouble and how to discover if that reason is your problem:

Location. A weak cell signal requires more battery power to operate the cell service radio, and that power usage heats up the phone. Check your cell signal strength; less than 2 bars means the phone is working harder to stay in touch with the cell tower. If you don’t have a WI-Fi signal available, there’s nothing you can do about it, but if Wi-Fi is available and works OK for voice calls, disable cell service by doing this:

  1. Enable Airplane mode - hold the power button until a menu appears, then chose Airplane mode.
  2. Start the Settings app, tap Wireless & networks, then tap the checkbox for Wi-Fi to turn it back on

If the phone is better behaved after the above steps, you can make step 2 unnecessary by modifying Airplane mode to leave Wi-Fi alone, using this app: Airplane Mode Modifier - Android Apps on Google Play.

Note that in this configuration, voicemail notifications won’t appear or disappear - that requires cell service. So remember to check for voicemail whenever there’s a missed call.

Data usage over cell service. This is another case of using Wi-Fi being much better than cell service. When data uses cell service instead of Wi-Fi, more power is required and more heat generated within the phone. To prevent this, connect to Wi-Fi whenever possible. When Wi-Fi isn’t available, disable sync activity (under Settings / Account & sync, uncheck both boxes), don’t stream music or video, and keep Internet surfing and social networking activities to a minimum.

***Apps gone wild. *** An app that runs continuously heats up the phone’s CPU and draws more battery current, which heats the battery as well. You can quickly check for an app problem with this widget: Temp+CPU V2 - Android Apps on Google Play (after installing, long-press a blank area of any home screen, choose “Android widgets”, scroll the list to find “Temp+CPU V2” and tap it). Set the display timeout to 1 minute or longer, and watch the widget. Within 30 seconds, the CPU speed should decline to 320MHz and the CPU usage to 5% or less. If it doesn’t, one of your apps is busy. You may be able to identify the guilty party with Usage Timelines Free - Android Apps on Google Play.

[P.S. If you have done Move As Many Apps As Possible To The SD card on your phone and then install Temp+CPU V2, the widget will improperly put itself to the SD card. You’ll need to move it back to phone memory in order to use it. I’ve notified the developer about this apparent oversight, so hopefully this note can disappear one day soon.]

***Charging. *** Earlier I talked about 3 causes, so this is a bonus. Obviously charging doesn’t reduce battery life, but when the battery runs down too quickly, you’ll want to plug in to a charger and keep using the phone. That is often not a great idea! Charging increases the battery’s temperature further and the phone may stop charging or become unstable when too hot. And charging a hot battery reduces the battery’s overall lifetime. So whenever possible, power off a hot phone for at least 15 minutes before charging. If the causes of overheating and fast battery drain have been eliminated, it’s OK to power it back on and charge with the screen off (the phone asleep), so you’ll know if a phone call comes in, but aside from phone calls or texts, avoid using the phone while it’s charging.


If you need to cool off your battery before charging, take the phone out of any protective case; they act as insulation. Especially silicone, they make oven mitts out of that stuff. You could also remove the battery from phone.


I have had these problems the entire time I have had the Defy XT557. I would really like to hear from others that had these issues, that have upgraded to a Moto G or Moto X, and what their battery and overheating experiences have been. My defy will die in less than an hour & a half if I use the GPS… If I try to charge it while using GPS, it gets burning hot.


The problem with built-in Google Navigation on the Defy XT is well known. It isn’t the GPS itself that causes phone heating and battery usage on the Defy XT, it’s apps’ use of CPU and 3G data usage, both of which are fairly intensive with Google Navigation.

The solution is - don’t use Google Navigation. Use an add-on “offline” GPS that doesn’t require data. For example: GPS Navigation & Maps - Android Apps on Google Play. (Note, before adding too many largish apps to the phone, make sure you’ve optimized it as much as possible: DEFY XT: How to increase space for apps and avoid the “low memory” warning.)

Regarding the Moto X / G, both phones handle 3G data without as much battery loss and the CPUs in those phones are more capable while using less power. So Google Navigation on the newer phones is no sweat.