Herman30, No fear, I have no intent of putting something that's likely to "kaboom" on my head!
Using a cheap headlamp with good batteries is one thing, a cheap headlamp with cheap batteries is quite another.
haertig, Yup!, it's definitely quite bright indeed though I don't think it's double what a car headlight can put out. As Tjin pointed out eBay lumens don't seem to be very accurate, I've been looking at these types of headlamps for a while and I've seen some claim to be 10,000, 20,000 and even up to 50,000 lumens!!