Anyone Know Why?

[Toulouse42]

I just recently bought a Nitecore LR12 Lantern (1 x 18650 / Cree XP-L HD V6). It claims 900 hours at 1 lumen for the lowest setting. I don't know if the claim is accurate but I'm currently testing that. I also own a Nitecore MH20 (also 18650 / Cree XM-L2-U2). That only claims 235 Hours at 1 lumen. Both flashlights claim a max of 1000 lumens. I know nothing about the science of LED lighting but can someone shed some light on the apparent huge difference in these claims.

 

[lightfooted]

Basically your MH20 is old tech. It uses an older, more power hungry LED for the light source. Yes the specs may be similar but the XP-L LED in the newer lantern is more efficient at producing light. It's the coolest part of not using a burning wire to emit photons. Advances in the manufacturing of LEDs allow for improvements that are significant and actually matter. Kind of like how we can now store several times over the amount of information that just ten years ago was considered the maximum possible.

 

[Toulouse42]

Thanks for that. Exactly the level of scientific explanation that I can follow. I had no idea that the improvements at low lumen settings were quite so great. So many manufacturers like to quote max headline figures that sound great but aren't too important in the real world. Lower settings or moonlight - well that's another matter.

 

[LEDphile]

XP-L and XM-L2 use the same die size and aren't more than a single generation apart, and the binning ranges overlap. So the difference isn't due to LED performance. More likely, things like driver efficiency at those low currents, parasitic draws inside the light (e.g. a microcontroller), and battery self-discharge are the reason for the runtime differences (assuming that both manufacturer claims are accurate and measuring the same way, of course)

 

[zs&tas]

I would bet a slight increase in driver efficiency, a definite difference in brightness although claiming 1 lumen but prob more likely is the claims are small printed with different battery capacities too !

 

[thermal guy]

Yes this is driver related for sure.

 

[Flashlightmaster2021]

Basically your MH20 is old tech. It uses an older, more power hungry LED for the light source. Yes the specs may be similar but the XP-L LED in the newer lantern is more efficient at producing light. It's the coolest part of not using a burning wire to emit photons. Advances in the manufacturing of LEDs allow for improvements that are significant and actually matter. Kind of like how we can now store several times over the amount of information that just ten years ago was considered the maximum possible.

wow this was really useful info

 

[Toulouse42]

zs&tas. Yes the MH20 is tested with a 2600 battery but the LR12 with a 3400 Mah battery. That aside it must be a driver issue. I have noticed that the lower/lowest outputs vary widely in performance even with emitters of similar ages. For example my Eagtacs (at lowest levels) do not perform too well but my Olights do. I have an Olight S2A Baton (2 x AA) that claims 0.5 lumens for 1200 hours. I haven't tested that but have no reason to disbelieve it. Compared to other 2AA lights that I own it seems very efficient at lower levels.