Darklight wrote:. . . I do not see mounting the battery inside (mine is at about 45 degrees from side to top) a major safety issue. . . .
You are entitled to your opinion on this, but I would hate to see such an idea spread. If a rock hits your helmet where the battery is located, that force will drive the battery into your head. Same is true if you fall and strike your head against rock where the battery is located. The result will be entirely different from the result if no battery were there.
Dwight