I am under the impression that the battery thing is a thing of the past. Mine has no battery and you can dial it from 9 to 13. I use it on the lowest setting.
When trying them out, I took along the flash to my camera. This helmet allowed me to see all the details of the flash lense without any after affects. When I go to use mine, I shine the trouble light right at it. After a few seconds it darkens and I know that it is ready. Turn the light on again and it reacts instantly.
I used to worry that if it didn't fire, my eyes would get burned. Well that has happened with no ill affects. Sometimes if there is an object in the path it can block the light to the sensor. All that happens is you see a big blob with no detail. You just cut it and start again.
