AA battery question

[guiri]

Guys, I had preordered one of 4sevens new lights but I had chosen the CR version due to the higher capacity but I started reconsidering because I have a shitload of Eneloops in AA at home.

So, I looked at the specs and it says

* Runtimes on one AA
Max: 130 lumens, 50 minutes
Min: 3 lumens, 45 hours or 1.9 days!

* Runtimes on one R14500 (protected only)
Max: 130 lumens, 80 minutes
Min: 5 lumens, 60 hours or 2.5 days!

Now, I'm looking at rechargeable ni-mh in AA and other stuff and they run at around 2400mAh or so vs the 750 for the protected cell.

So, my question is, what AA are they talking about that has shorter runtime than the protected at 750mAh and does this mean much longer runtime with a Ni-Mh AA or one of these?
http://www.batteryjunction.com/xl-060f-xeno-aa.html

What's the advantage of one of these vs a regular Ni-Mh at the same mAh rating?

I am soo damn confused.

 

[mdocod]

you have to look at watt hours to compare cells with different chemistries and different voltages.

A 3.7V li-ion cell with 750mAH capacity has 2.775 watt hours of "juice" available.

A 1.2V NIMH cell with 2400mAH capacity has 2.88 watt hours of "juice" available.

So they really aren't much different. However: One thing that may be a bigger factor is that the driver is probably more efficient when working from the 3.7V source than it is running from the 1.2V source. When the supply voltage is closer to the drivers output voltage, the driver will waste less energy as heat and operate at lower inlet currents.

Eric

 

[guiri]

Ah, didn't know the R14500 was 3.7 volts.

Thanks

George