RONALD V No risk. They are completely hermetic

ANDRE V No they do not. There are multiple battery options for this headlamp. I chose the 2-CR123 option as they are lithium, and work incredibly well with LED light technology for both brightness levels and longevity. Nevermind the fact that they weigh half as much as an alkaline battery. I own multiple headlamps and have used them to the point of straps falling apart and I have never had a headache or any other negative physical reaction from the power source. Cheers!

JEFF K no they don't. However the light does go through the batteries fairly aggressively. They aren't cheap, but they light is well built.

SHERRY C I really don't know if there is a health risk with the batteries close to the head. However I do not like the fact that this headlamp uses the CR123 batteries. They don't seem to last and I have had to abandon this headlamp for adventure racing because of the unpredictable battery life. One of my teammates really liked this headlamp but finally gave up because battery issues. These batteries are not cheap or easy to find especially if you race internationally. .

CESARE C NO - I have used this lamp for many night runs, the batteries will die on you before they start to leak. The enclosure is also water tight. Never had a problem with the batteries, never got water in there, even when running at night in the rain. As far as I am concerned, for me its a non-issue. The version with 4 AA batteries, allows for recycleable batteries, but its just grams more than the 2 CR123's. Either way, the battery comparments are water tight, as I have both. Hope this helps. Tony C

SunnySports S Great questions! 1) Yes, the main beam is always a white beam, it is the 4 LED ultra-brights that you have the option to change the color of (even though its 4 ultra-bright they are all only one color, whichever color you choose). 2) Yes, the red LED ultra-brights can stay on continuously. 3) There is a total of 35 hours of burn time no matter how you slice it, but depending on if you have on the main beam or the 4 ultra-brights can effect how long you can keep it on in high beam. The main beam (white- 130 - Lumens) you can keep on high beam for 1 and half hrs, then it automatically switches to low beam to finish of the remaining 33 or so hrs. The ultra- brights (red - 100 Lumens) you can keep on high beam for 5 and a half hours, and then it switches to low beam for a remaining 12 hrs of burn time. 4) Yes, the outputs are adjustable, you can switch between high beam and low beam. No, you can not have both the main beam and the ultra-brights on continuously together. 5) There is not a newer model. Technically Princeton Tec is putting out a catalog this year with the Apex Pro which they are branding the 2010 model but I spoke with one of their experts and he said it is the same model just re-branded because customers want a new model. It is the same styling same specs, nothing has changed at all. Stay safe and have fun out there! Neal

SunnySports S CR-123 Lithium batteries will outlast lithium AA batteries. If your hiking at night or even just camping, you will want the light to work when you need it. Lithium batteries work very well in the cold. CR-123 batteries are very easy to get. They are used in many of todays cameras, flashlights, etc. Have Fun Out There! Carl