LED Lifetime Issues When Using RCR123A in Older CR123A Lights (e. g. Nuwai QIII) ?

I have an older Nuwai Quantum III light and would like to run it off rechargeables. I think it is the original version, since it has the reverse clicky.

I tried those 3V limited LiIons several years ago, but the batteries died after few cycles, it looks like the circuitry of those batteries couldn't deliver the hight current.

I have other cheap 3W lights, that use RCR123A batteries. Testing those batteries in my QIII revealed no initial problems, but the much higher light output has me worried about temperatures and LED lifetime.

Searching the forum, I found several older threads where people report using the RCR123A in their QIII light with no problems but some words of caution, too.

Since it now has been a while, can someone comment on any issues when running the old lights regularly for longer periods on the rechargeables?

I don't know anything about that specific light. It sounds as if the light goes direct drive with the extra voltage. Your biggest enemy will be the heat. That will kill the emitter if you run it with too much heat for an extended period of time. If you are careful, it sounds like you will be ok. Perhaps you can't run on high for more than a few min? It will depend on how hot the light becomes.

The 3.0v RCR123s may be a safer bet as I assume you are referring to the 3.7v RCR123s. The 3.0v RCR123 is actually not 3.0v off charger but will be at least say 3.6-3.7c hot off charger but may go down to 3.2v on load.

I have some old 3.0v RCR123s that were from AW before he discontinued and lights like my old Fenix P1 (3w Luxeon) and Dorcy Super 1watt do run hotter much faster compared to when on CR123 primary if any heat on primary.

The older Q1 with the LuxI cannot be run off RCR123As but the QIII with the LuxIII has been used by CPF members with RCR123A for many years - until Nuwai got dethroned by Fenix. That was the reason to pay more for the QIII - the ability to go from 30 lumens to 75 lumens with an RCR123A.
Remember the QIII is one hefty light 94mm x 28mm unlike the Quark MiNi 123 81mm x 22mm. As many current CPF members are using RCR123A in the MiNi with no problems I would not worry about the QIII.
Just make sure you have a QIII and not a QI.

Lighthound is offering an AW LiFePo4 3V RCR123A that requires a 3V charger. Think it gets 3V from the different chemistry instead of that old flakey clamp circuit. Maybe ask in the batteries about that battery. OOPS I guess those were the ones that were discontinued.

Thanks so far. I'll either look into the LiFePo battery, 3.6V off the charger sounds more reasonable than 4.2V - or I'll guinea pig the light and see how long it will survive. It would just be a) a shame to ruin the light and b) rather inconvenient to be caught in darkness. The trend goes to a second light anyways

I have had my QIII running on the 3.6 volt cells from day one. It does get hot if left on for a few minutes. The finish is worn, the clip was taken off years ago but the internal works are still plugging along. I did put a new glass lens in it recently as the old plastic one was so scratched and fogged it lost a lot of light.

It is still my favorite pocket light.

s.urfer said:

Thanks so far. I'll either look into the LiFePo battery, 3.6V off the charger sounds more reasonable than 4.2V - or I'll guinea pig the light and see how long it will survive. It would just be a) a shame to ruin the light and b) rather inconvenient to be caught in darkness. The trend goes to a second light anyways

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The LED will not see 4.2V because under 1 Amp of current, the cell voltage will drop. Just do it!

I've had 4 QIIIs. Sold 3 of them and kept the nice rare green one. I've had the original LuxIII, SSC P4, and now a Cree XR-E P4 in it, all run off 3.7V Li-Ion with no problems. The boost driver will simply be bypassed when running 3.7V Li-Ions. There's some heat, but as long as you hold on to the light, your hand dissipates enough heat to not damage anything. You'll know if the LED's overheating as it will change color in use. As long as the tint doesn't shift, the LED is likely fine.
The QIII, after all these years and generations of lights and LEDs, is still a favorite light of mine. It's a bit bulky by today's standards, but it feels great in the hand and has a beautifully smooth beam (even with the XR-E).
The 3V R123s you had may not have been protected, which may have been why they died prematurely (my dad has a 4 3V R123s that are unprotected). The protected ones should last you fine and work great in a QIII.