I mention the dangers of Lithium batteries just as a safety consideration. I had several electric planes with lithium batteries, but quit using them after having to kick one out of the garage because it went off like a smoke bomb and caught fire. It had crash damage, and when I squeezed it to remove it from the plane, it shorted out internally. If it had gone off while still in the back seat of my car, the car would have burned down. Lithium batteries do have the best power to weight, and are very popular, but people new to the hobby must be informed about proper handling and charging techniques to minimize the danger.