Runtime question

I have a LD12. After I found out it can be lego with Quark 2AA body with Quark tailcap. I legoed them together. The brightness seems the same, does that mean the runtime increased? Thanks in advance.

Anyone?

Yes runtime will be extended. Brightness will be the same!

Thx buddy.

That's perfect! I think the brightness is good enough for most of my tasks. Any chance the runtime will be close to double?

dealgrabber2002 said:

Thx buddy.

That's perfect! I think the brightness is good enough for most of my tasks. Any chance the runtime will be close to double?

Click to expand...

It depends on which chemistry you use and how the LD12 head responds to voltage change with cell discharge. Roughly speaking with NiMHs, you'd get a bit over double. With alkaleaks, it will not be quite doubled. With Energizer Lithiums, it will not quite be doubled, either.

Nice. I use nimh most of the time.

Another question regarding runtime for the same LD-12 mentioned in my original post. The brightness is the same regardless of using 1AA, 2AA, or 1 CR123. Which gives better runtime?

2 AA eneloop
1 Surefire CR123 (expire: 2022)

Moved to LED Flashlights - Norm

What to post in the General Flashlight Discussion Sub Fourum.

The 2 Eneloops.

In series, add voltage and mah stays the same. So V for 2xNiMh ~ = 1xCR123, and mah would be 2xNiMh ~ 2000 (2500 for XXX), 1xCR123 ~ 1500. One other alternative you have, is the 1xCRAA/14505 cell, which is essentially a CR123 equivalent in a AA body - unfortunately, it's been out of stock for sometime now (although I have small stock of them). Keeping the 1xAA body (and carrying the 2nd cell) would give you a lot more options, like scavenging AAAs and 9V cells - which for me = emergency runtime.

Since you seemed very concerned with emergency runtime (as I am - we've discussed the D40A in PMs), I'd just go back and use that LD12 body with Quark head if I were you... between its ultra-efficient AND bright useable moonlight mode, broad voltage support and Lego-able bodies, and ability to scavenge any cell with <19mm diameter, it's the ultimate emergency light for me. I know Fenix claims ~ 300 lumen-hours of efficiency across all its modes, but I read SB's tests, and adjusting for battery and lumen scale difference, the LD12 doesn't seem significantly more efficient than a Quark to me.

Thx reppan,

I already have a Quark 2AA with 1 AA and CR123 body. Was just thinking which lego was better. Thanks again.

When using 2 AA batteries, the boost circuit will be more efficient, since the input voltage(~2.4v, NiMH) is closer to LED Vf(~3.2v) compared with 1AA(~1.2v, NiMH).
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This is true for most regulated-output boost circuit. LD12's shouldn't be different.

So theoretically, Runtime(2AA) > Runtime(1AA) + Runtime(1AA)

Also, input current could be reduced, thus improving reliability.