I fly long range fpv airplanes and was always worried about crashing and not being able to find the plane. So I came up with this setup to keep the RX running even if the main battery is ejected. Depending on how you set it up you can also keep a GPS running as well. If you want to run a GPS this is made to fit the HGLRC M100 Mini GPS

I included STEP and Fusion files as well so if you're running ELRS or something else you can change it to work with your setup. 

The battery is a small 180mah lipo. these will work. As long as the dimensions are 25mmX17mmX7mm. 

The little module is a HW-775. you can get it here. They're cheap so pretty affordable to outfit your hangar. It will charge the battery while your plane is powered and you can shut it off with either the button on the board or you can add an external switch.  

If you're not running a FC and you want to run a GPS there's a few different options, These work well or this. or you can change the inputs on the crossfire RX for GPS input. Channel 3 is GPS TX and Channel 4 is GPS RX. Make sure to change the inputs on your Crossfire TX. 

For the print you'll need to add supports to the lid. I printed mine pretty fine at .1 with a .4 nozzle. I used ASA filament for some added heat resistance. Everything else is pretty self explanatory.