Headlamp Input

[skiguy]

Just ran across a report that Petzl published a warning that lithium batteries can damage their LED lights:
http://www.outdoorsmagic.com/news/article/mps/UAN/4127/v/1/sp/332933698389328935310
http://en.petzl.com/petzl/LampesNews?News=159

Princeton Tec says lithiums are ok with their LED lights: http://www.outdoorsmagic.com/news/article/mps/UAN/4361/V/1/SP/332933698389328935310

Doug

Great links as usual Doug. Intrestingly my initial above post about Lithiums damaging LED's was related to a disscussion with a Petzel Rep about a year ago. It seems as though it is Lamp dependent to a degree not just Liths vs. LED. vs. Alkaline. Many of my mental maps on this issue go back to the days of the Easter seal Torch. Back then a big momma Lith D cell kicked butt over it's alkaline sister. Do you think that todays AAA and AA alkalines have any advantage in cold situations over the big alkaline D's of yesteryear? For example Petzel lists the MyO xp as a lamp NOT to use Lithiums with...so therefore is one still expected to get good cold weather performance now with alkaline? Or go find another lamp... I have always relied on Lithium for Cold weather use and have seen increased performance over alkaline in all situations. I guess I liked it better when I could carry extra bulbs and not worry about my LED's going on the fritzzz. I never worried about having back up headlamps before but IMO LED has put me in that position over having spare bulbs and Batteries. Gotta go and find out if my MYO is a MYO or a MYO xp

 

[DougPaul]

Back then a big momma Lith D cell kicked butt over it's alkaline sister. Do you think that todays AAA and AA alkalines have any advantage in cold situations over the big alkaline D's of yesteryear?

Not fair to compare different sizes of cells. And you already know the answer if you compare same-size to same-size.

BTW, there used to be lithium D's, but they were 3V. (They probably still exist.)

I guess I liked it better when I could carry extra bulbs and not worry about my LED's going on the fritzzz. I never worried about having back up headlamps before but IMO LED has put me in that position over having spare bulbs and Batteries.

No equipment is failure proof. I always carry a spare light or two. (Caver's rule: always carry at least 3 sources of light...)

Here is a datasheet on lithium AA cells: http://data.energizer.com/PDFs/l91.pdf. Look at the discharge curves--right at the beginning there is a voltage spike which is higher for lithiums than for alkalines. This spike is most likely the trouble maker. If you wanted, you could run the cells down just a bit (in something safe) to get rid of the spike.

I also discovered a note in my notes about the Petzl warning dated Sept 2006. So I guess it is just nothing new...

Doug

 

[daxegraphix]

Thanks

Thanks for the headlamp info. Lots to chew on.