Inova or Arc for using up 123s from Surefires.

When they are too dead for a Surefire which would get the most use if any out of the batteries an X5T or LS?

I move them from my SF, to my X5T, to my LS, in that order. TX

IMO the X5-T doesn't make good use of used up 123s, but little light is better than no light.

I move 123's:

Freshest 123's (3.27 V no load) in SF 2.3 Amp (P61, P91, MN61) and 3.7 Amp (N62) LA's.

I move from above into 1.0 Amp to 1.2 Amp LA's (MN03, P60, P90, Scorpion, Legend LX) and to the partially regulated ARC LS and to my X5 and X5 T roughly when no-load voltage is around 3.05 V.

(edit: voltage at movement time is determined by visual dimming, not by anal-compulsive voltage measurements.)

I move from the above into my E2 with KL1 (more effectively regulated)from the above at roughly around 2.95 unloaded V per cell. At this voltage level there is no need to put up with dimmer ARC or X5 output.

I kill the batteries in a 9P with KL3. I place the weakest battery at the cathode end, second weakest battery in the center, and run them until the light dims at which time the weakest battery is probably effectively dead. As two batteries will run the KL3, any help at all from the almost dead third battery is gravy and prolongs the life of the other two batteries. I also have good success using one weak 123 with a fresh alkaline AA in a 9P with KL3 as long as the two batteries can combine to deliver approximately 350 to 400 mA at 3.6 V or above.

I may play the same KL3 battery kill game with a KL1 with my on-order Doug Speck UBH, but I'll more often run it with 2 A NiMH rechargeables as an "Alternate EDC" (Have I coined a CPF Oxymoron?)

My willingness to play this game is moderated by my needs for run time between changes and the proximity of my voltage-graded used 123's.

Thanks for all the info. lemlux, if I weren't an EE I would have a dozen questions for you. Since I am, I only have 11.

I would suggest running 2 used 123s on a Opalec newbeam. It's going to take a long time to get the light to fall out of regulation.

Even though I'm still on the original batteries supplied with my X5T, my bud at work has an M2. When his batteries died in that light, I tried them in my Inova. Well, the batteries barely had enough oomph to even make the LEDs glow. My plan is to switch out the batteries of my E2e after significant usage... say, maybe 30 min combined time. Even after using half their juice, the 123s should still make the Inova produce hours worth of good light.

When my light starts to dim in my SF, I can usually get 2-3 hrs use out of them on my X5. Not as bright as new ones, but plenty useable. TX