Lithium still bothers me in aircraft, when to the battery point in my build I am going to look seriously into the new super Capacitor batteries. All the light weight and most of the size benefits of the Lithium type and none of the dangers from what I've read, looks promising

Here is some interesting info on it.
http://www.instructables.com/id/The-...er-Capacitor-/

https://www.youtube.com/watch?v=z3x_kYq3mHM