Unprotected Li-Ion question

[cmaylodm]

How easy is it to tell when to stop using an incandescent light when using unprotected cells? I would like to run an MN16 on a couple of 17670s, but AW is all out of protected cells. The only other light I have running on unprotected cells is a small 1xAA LED light, which runs for so long that I never have run the batteries down past 3.4v. However, with the ~30 minute runtime of the MN16 on 17670s I am a little worried about overdischarge.

 

[Strauss]

Some people have different views on this topic. I think a well educated flashoholic as yourself will have no problems running unprotected cells.When you start to notice the MN16 agressively dropping in output(more noticable is the "yellow" color of the beam), it's time to charge.

Personally, I just top off my cells if I have used a light for awhile and feel the need to. And it helps to know your apprx. runtimes with your set-up, so you know when to start really watching for the quick drop in output. Li-ion cells have a pretty flat discharge curve, but when they get down there, they drop quick...hence the "yellowing" beam.

I say go for it...plus they are cheap I gave you an un-protected cell with the L5 FYI...

 

[cmaylodm]

It's actually that L5 that broke my fear of unprotected cells. Now I am more worried about ruining some cells by overdischarging them and reducing their lifespan, but if it's not too hard to tell when its time to change them (like in the L5) then I think I'll snag some unprotected cells to hold me over until AW gets protected back in stock.

 

[Strauss]

It's much easier to notice the dimming with an ican over an LED......

 

[Curious_character]

It's much easier to notice the dimming with an ican over an LED......

The Cree, Seoul, and Luxeons I've tested produce around 1% or less of the light output at 2.5 volts (a safe minimum voltage for a Li-Ion cell) than they do at 3.7 volts. It would be very hard not to notice a 99% drop. Of course, if the supply is regulated -- whether LED or incandescent --, all bets are off. And admittedly, regulation is much more common in LED lights than in incandescents.

c_c