Help me troubleshoot my new Ranier/CPF Special

I bought one of the CPF specials off the "Sell" forum, and the seller included a set of (3.7v 750mAh protected?) RCRs with a charger like this one:

http://www.lighthound.com/sales/rcr123_protected_rechargeable_battery_kit.htm

Except the batteries I got are blue-wrappered and say:

Li-ion Rechargeable
RCR123A

When I got it I popped in one of the batteries and turned on the light, and it was very bright, as I expected. It ran for about, oh, maybe 20 minutes and then it dimmed noticeably. At that point I thought "OK, time to charge that battery." So I charged it and now when I put it (or the other, or one of my known-good) 3.7v 750mAh RCRs into the light, it only comes on dimly.

So, could I have damaged the light by running it (handheld) for as much as a half hour? Maybe all the batteries I have tested with are bad or not fully charged? What would be a good set of steps to troubleshoot why the light is not coming on at full brightness now?

I have a digital multimeter, so when I get home I plan to check the resting charge of the batteries, in volts. Otherwise, assuming the batts are at or near 4.2v, what should I look at next?

Edit: By "comes on dimly" I mean it still lights up, but it is much less bright than the nekomane-bodied CR2-powered Fenix L2P I also have sitting on my desk here.

The batteries are about fully charged at 4.14v. Maybe I'm just confused about how bright it was at first and this is how bright the light is going to be (still brighter than with a primary in it).

I guess I will chalk this up to New Flashlight Syndrome. :whoopin:

It should be obviously brighter on R123 than disposable. I've never seen a CR2 Fenix L2P in action, so can't comment on that comparison.

if it helps you can take a look at my beamshots page (sigline below), to compare the CPF Special I have with the L1P/L2P on AAs as well as my other lights and see if it tallys with what you're seeing. my CPF special seems to be somewhere between lvl 1 & 2 of my U2 in hotspot brightness.

If you've tried different batts (and apparently you have), there has to be something amiss with the LED. My Special is painful to look at when it gets within 30 degrees of my eyeballs. If it isn't painfully bright, then it's not right. I realize that isn't very helpful, but it's all I have.

I don't mean to cast aspersions on the planning in the CPF special but I
believe its Direct-Drive and with a RC123 its probably brighter than any of
my other single-cell 3W lights, even the U-bins, maybe with the exception
of my orb-raw U-bin, one of the the bright U-bin raws in the first batch.

I have been thinking about how it can be so bright in DD drive - ie brighter
than my U-bin Lionheart and U-bin Nuwai Q3, and it seems to me that the
only way it can achieve this is by either being a U-bin itself
(and a freakishly bright one at that), or by maybe having an
H Vf which would probably overdrive the luxeon to dangerous levels for a
good lifetime, but would account for the brightness on an RCR123.

Obviously I would prefer the led to be a U---J bin rather than a T--H bin,
because this would be far safer for running a RCR123, but because Peak
don't actually disclose the bin, I have no means of knowing.

The light certainly gets very hot very quickly and in these cases I am always
nervous to keep the light on for a prolonged length of time (which maybe 20
minutes could be considered to be)

Maybe Peak can advise Rainier owners on the bin code of their leds and the
length of time it is safe to keep these on for?

(So, could I have damaged the light by running it (handheld) for as much as a half hour? Maybe all the batteries I have tested with are bad or not fully charged? What would be a good set of steps to troubleshoot why the light is not coming on at full brightness now?)

I always drain two rcr123's in my Brass Rainier on nighttime walks (manybe 90min) almost always on and it is still insanely brite. Also have left it in candle mode for 20min or more. It gets so hot you really cant touch it when it's been sitting like this. Still insanely brite. Could the screw under the split ring not be making good contact?
Good luck with your sick CPF Rainier

I think it's best to contact Robyn, 'cause we'd just be guessing.

That's exactly what I did. I sent the light to Peak and they will be checking it out for me. Hoping for the best. :candle: