Fat Shark FPV Goggle Battery with ON/OFF Switch and Power Indicator

thingiverse

Back Story Switching between flights, I unplug the barrel jack from my goggles to prevent wasting power while they rest on my forehead. This precaution is likely a common habit among many of you. My problem arises when it's time to blindly plug it back in with the goggles still on my face. I struggle for an embarrassingly long time, misidentifying the headphone jack as my target and futilely trying to force the battery connector into it. Perhaps being this clumsy with my hands is a valid reason why I shouldn't be piloting drones. You may have a point. Functionality To solve this issue, I designed a battery pack that can remain plugged in and simply switched off when power isn't needed. While working on this project, I also added a power indicator LED. The LED functions differently than you might expect, but feel free to build it your way or omit it altogether. Build Details In my design, the pack glows brightly at 8.2V and dims down to turn off around 7V. At its brightest, the LED draws only a negligible 1mA of current when turned on. The wiring diagram is attached, but I basically added a Zener diode in series with the LED to create this dimming behavior. These connections are simply soldered point-to-point. Through experimentation, I found that using a Vz value of 5.6V works well. If you prefer not to use a Zener diode, you can replace it with an appropriately sized current limiting resistor. The wiring is tight but has enough room for all the components. The unit's overall size was kept down by minimizing the space between parts. Four M3x14mm screws fasten the front and back pieces from the back side. I made the front and back cover using PETG, while the strain relief block is made of TPU. TPU or TPE is recommended for this specific part. As you can see in the images, the inside of the strain relief block is designed to be cinched down on the cables with a small zip tie that stays concealed within the case when completed. For this reason, the part was designed with the expectation of using a reasonably flexible material. The TPU I used has a Shore hardness of 95A and worked well, but I wouldn't recommend going any higher. Happy building! Please share your makes! Parts List: * 2S JST-XH cable * 18650 Li-ion Cells * Two Position Switch * Zener Diodes (optional) * 5mm Blue LED * M3x14mm Thread Button Head Hex Screws * Hatchbox Blue PETG Filament (used for cover) * SainSmart White Flexible TPU (used for the strain relief block)