This is one mother of a flashlight, and at about thrice the power of a good car headlight, its got quite an impact. The whole build cost me about $50 total, but buying everything new would increase the price a bit. Its got about a 2 hour battery life on a 12V, 7.2Ah lead acid battery. It uses CREE XM-L LEDs for intense light and longevity. The build requires minimal knowledge, but it is pretty easy to destory parts instantly if something is assembled wrong. And unlike commercial flashlights, this will not heat up at all, and will actually pump out all 3450lm for a long time.
However, I must make some notes on safety.
First, this may just be a flashlight, but it WILL cause damage if you look too close. Don't point it in someone elses eyes, or look at the spot on a bright surface too closely.
Wear welding goggles when first testing it, or any other time you have a chance of accidentally looking directly at the LEDs. Wear sunglasses if you test it inside. It may seem like petty over-safety, but this can and will cause damage if you use it wrong.
Point is, don't be stupid or complain that I didn't warn you.