After watching too many videos of LiPo batteries catching fire, I was really uncomfortable with the thought of flying with a potential fire hazard that could melt the harness or the glider lines. That would be an extreme scenario, but looking at the size of the balls of fire that lipos can produce, it didn’t seem like a good idea. Here is my attempt at a poor man’s ejectable battery box.
This box fits 2 or 4 of the 6s 22000mAh LiPos (like the Bonkas).
It uses the existing holes on the back plate of the frame for support.
- thought about making it aluminum, but saw lipo fires documented at over 1300 F and lasting over 15 minutes. Aluminum would melt at around 1200 F. So, I went with steel. Heavier, but withstands about 2500F. Some of the High temperature resistant (fire proof) carbon fiber would be the ideal material, but I couldn’t find any. Plus, it seems like even if the carbon fiber itself resists the fire, the resins might not, so it would have to be some very specific material.
- No welding used. It is all steel rivets connecting Home Depot 0.019 Steel Sheets. Finished with decorative carbon fiber vinyl.
- Wanted some sort of mechanism to eject the box in case of fire.
- the bottom is opened, to try and release pressure in case of fire. The opening has a flat to try to divert the fire/gases down and back, away from the pilot / harness / glider.
- Total weight - 1540g
Hope to inspire someone with a lot more talent and tools.
I have tested the contraption and it releases upon pulling the ejection cable. So far, my tests have not shown the batteries to get hot, but I have not done a full throttle till the battery dies. That is one thing I worry, wether the batteries are going to get hotter because they are in a closed box.
This is coming out of my unit as soon as Paul releases the official OpenPPg battery box.
Here it is: