@Benson:
I can name one specifically: Solarforce XM-L 1 mode 3.7 volt module....they also make a 3 mode and a 5 mode as well as 5 more XP-G modules with a 3.7 volt upper limit. I have seen other similar rated modules on a popular discount site.
A 3.7V module will fail on 2 Li-ions just as surely as on 3 primaries. I use some cheap dropins as well, but I've never had one rated for 8.4V (i.e. 2s Li-ion) fail or behave strangely on 3 primaries.
You said (emphasis mine):
Hotwire probably meant to recommend using a pair of 17500s which would allow your detective to use some of the P60 emitters...however it would limit the use to just the rechargeables as dropping in the third CR123A would overdrive and ruin several of the P60 modules.
But since those
several drop-ins would fry on
a pair of 17500s as well... I don't see your point.
I agree that quality modules are more than capable of handling up to 9 volts input...I've even seen some rated for 18 volts, but since they (3.7v modules) do in fact exist I wanted to be sure the op was aware that not all modules are designed alike. Check your voltages is the best advice here.
Okay... that doesn't seem at all like what you
said before. But on this, we're in agreement.
Okay sure, load voltages are generally lower than when just connected directly to the meter....but even at 3.6 volts each it still makes less than the incandescent P90's rated 9 volts which means it will be less bright than fresh primaries. Output...not runtime is what I was referring to.
:sigh:
Did you
look at the graphs?
Considering 1A:
the CR123 delivers 2.75V fresh; this means 8.25V for 3 (and falls off rapidly)
the 17500 delivers 4.1V fresh; this means 8.2V for 2 -- they start basically equal, with the CR123 slightly ahead for perhaps a half minute.
the CR123 quickly drops to 2.5V and stays more-or-less level to 30 minutes; this means 7.5V for 3
the 17500 doesn't drop off to 3.75V (x2=7.5V) for
25 minutes -- this whole time (except the first ~30s), it's brighter than the 3xCR123.
From there to about an hour, they're pretty much equal; at that point the 17500s drop out quite sharply, while the CR123s staggers on for a while at ever-decreasing voltage.
At
no point are the CR123s delivering a significantly higher voltage for any significant time, but the 17500s
are significantly brighter for the first third of the discharge. Saying the 17500s "will be less bright" is just not correct in any useful sense, even if it's technically "true" (by a tiny amount, for 30 seconds).
That's all assuming 1A (approximately = P90) -- you can compare them yourself at 2A, where the CR123s do
even worse!