Battery Percentage


Featured functions

  • Possibility to configure 3 different battery-sizes
  • Possibility to use the percentage on main screen as telemetry window
  • Telemetry window titles are user definable
  • Creates LUA control (freely usable switch)
  • Enable – disable alarms
  • LUA Control has freely definable alarm-point
  • Enable audio-announcement when alarm occurs – one for each battery
  • Possibility to select a switch for announcement of percentage
  • Choise of realtime battery-symbol on main-screen
  • Automatic detection of current-sensor with Ah or mAh values

Also available for DC/DS-14/16, difference is 2 batteries instead of 5. Battery-symbol on permanently.


In short: Copy the .lc (or .lua, the .lc is memory-optimized) file from github here to your transmitters Apps-folder, if there is a translation file copy the .jsn file to Apps/Lang-folder on your transmitter. Head on to “Applications” -> “User applications” and add the app. Guide on installation of Lua-apps available here if you need some more in-depth guide.

Setting up and usage – Battery Percentage with Options

After opening the application from “Applications” -> “Battery Percentage” you are greeted with main screen:


For DC/DS-16 there is only one screen:

Settings are self-explanatory, in order to use the app you need to select a sensor that gives you consumed capacity, this is same for all batteries. Voice-announcement, three times or just once, easy. Here you will also choose if to have telemetry-window with the real-time updating battery-symbol:


You can also define a switch for voice announcement. When switch is activated transmitter will tell you your battery percentage like “Capacity 85 percent”. Announcements can be made every 3 seconds. Leaving the switch on will result in transmitter telling you the percentage every 3 second.

On the 3 different battery-pages you will have to make some setting. If only one battery-size is used then no switch needs to be defined and settings for Battery 1 will be used. Settings are the same for every battery-size.


Change the label to your liking, set the battery total capacity and lastly the percentage value where you want the alarm to sound. Value of zero means alarm is disabled. 

If you want to use for example 3 different sized batteries you need to define a switch for every battery-screen, for example a 3-position switch would be perfect.

There is also possibility to make voice announcement with a audio-file straight from this application when alarm-value is reached. All batteries can have different audio-files defined.

Setting-screens for battery 2 and 3 are the same as for battery 1 except for the sensor-selection since the sensor is the same for all.

Using the percentage alarm for example in voice announcements is easy, just choose the corrsponding “Battery Alarm” switch from “Apps” in switch selection dialog:


There is a need for only one switch for all battery-sizes. When the batteries percentage is at alarm-percentage the switch will activate. (For example: “Battery empty, land now”)

The windows to main screen are added the normal way, go to “Timers/Sensor” -> “Displayed Telemetry” and add the desired window as usual, the name of the window is what you have defined as active window label, here it is “LiPo 5000mAh”:


Now you have the display on main screen and using the switch changes the telemetry window label, capacity and alarm-point (Note the window label):

tele_screen  batt_15_07

Above is the result, here is example on battery 1 settings, using 4400mAh pack with a window title of “LiPo 4400mAh” and alarm when percentage left drops to 25%:


Easy as that! Enjoy!

Version history

  • 1.0 Original version
  • 1.1 Added multi-language, languages available EN, DE
  • 1.2 Code cleaned, translations separated to own file for easier user-translation to own language
  • 1.3 Added French translation – Courtesy of Daniem Memin
  • 1.4 Fixed: Error when used together with all other apps
  • 1.5 Now possible to make voice announcement separately for all battery-sizes on alarm
  • 1.6 Possibility to choose of realtime battery-symbol on main-screen added
  • 1.7 Added Spanish translation from César Casado
  • 1.8 DC/DS-16 version published and small adjustment on 24-version
  • 1.9 Added Italian translation by Fabrizio Zaini
  • 2.0 Added Czech and Slovak translations by Michal Hutnik
  • 2.1 Added voice announcement
  • 2.2 Mixed improvements
  • 2.3 Improved memoryhandling
  • 2.4 Added telemetry window naming to 14/16-version
  • 2.5 Added automatic detection of current-sensor with Ah or mAh values


Some rules do of course apply!

  • Never use Lua to control a function that would take the model down if misbehaving!
  • Always, always test the function thoroughly!
  • If you do not know, then don’t!
  • RC-Thoughts or myself is NOT responsible for anything this application does
  • Applications are free to use (MIT-license) and linking to this page is encouraged!