I'm sure on a winning streak here lately. Just got it this morning, popped three Duracells in, and boy was I less than impressed. It goes through the modes. High is less bright than any R5 I own and more than twice less bright as my weakest XM-L. In the other modes, it's hard to see anything. And just when I thought this one was just way underpowered, it started flashing in low as though to tell me the batteries are bad. So I pull them out and put in another pair. Same result after about 20 seconds of use. I voltage-check all of them and the least of them reads 1.3. The only other time a light did this to me was when the driver went out on our work Inova.
After a pressure match which I won and got the 18650 in there, it stayed nicely and the light is about as bright as a non-pushed XM-L. Maybe as bright as my Manafont C8. But how does this explain the blinking and changing modes with 3 AAs are used? I expected resistance, but this makes it useless through and through.
The weak output is because alkaline chemistry can only pass a very limited current before voltage sag sets in. IIRC Duracells typically only deliver on ~..5-7A, so you are severely starving the circuit of wattage overall.
Alkalines will voltage sag tremendously under the kind of current a well driven XML requires. I am guessing you are pushing the cells into voltage sag and the DC-DC board is kicking into a kind of over discharge warning, as you would (ideally) need with an unprotected 18650. The other possibility is the the voltage sag is so severe that its also starving the EPROM and its behaving inconsistently from being under-fed Vin.
Ditch the Alkalines they will leak anyways under such abuse. Step up to Eneloops or stick with 18650. Alkalines can't hang with these kinds of lights.
Ok, I hear you, but that defeats the point of having a light that can use AAs since most are store-bought emergency batteries that will be alkalines. They needed a disclaimer saying not to use alkies then. No one could rely on this sort of performance--no one. It's performing okay on 1 18650 and I'm not noticing dimming, but the idea of advertising using a particular kind of cell needs to be done only if the light can deliver. Most AAA cheapies can run bright for a good while on the worst of cells, which means it doesn't make sense to advertise this as AA compatible if it can't do the same. Heck, I can just use 26650s or 18650s rather than bother with buying special AAs, but that's not why I bought the light. It just doesn't make sense.
I'd agree with Kramer5150 that it's voltage sag and the cells not being able to deliver the higher currents. Rusty's measurement showing "1.3v" sounds to me like the cells are pretty well depleted already. Alkalines tend to only work while fresh out of the pack and then only for a few minutes (or seconds depending on current draw demand). Just ask oldbobk about his D cell alkaline Mag project - a total no-go. I believe drivers do goofy things when voltage gets too low. I also believe the driver is going into it's low voltage protection mode. On my custom Mag 3C (tested on 3 AA NiMh cells) the light ran great and then started not going into high mode and kicking back into low and flashing. Changing to fresh charged batteries put it back to normal.
About the cheaper lights running in alkies - those cheap lights don't pull too much current, OR (more than likely) are direct drive. Some may even have a boost driver so as to make better use of alkalines. I would say the boost driver is the best way to go if you want to run on alkalines, esp. if you want modes. (Anyone agree?)
@Tecmo: The modes "work," they're just even lower than they would be.
@Garry: But this still doesn't deal with the accountability issue of making a high-power light that allegedly runs on a certain type of cell, and yet doesn't. As for the voltage, the lowest was 1.3. The highest was 1.5 and 1.4. And 1.5 to 1.2 are normal range for AAs, right? So again, why no anger on the fact that this light simply doesn't perform as advertised? It also doesn't always change modes unless you press it in more than a tap.
I'm comparing it now to my Manafont XM-L C8 in the dark closet. It's about the same or less, only throwier (as far as the eye can tell). We'll see what kind of fun I'll have tonight. Guess I got me a new 26650 light.
How was the light advertised to run on alkalines? I believe the light was only advertised to run on "AA". "AA" doesn't necessarily imply alkalines. I do however agree with you that the sellers should specify that NiMh's should/must be used (and possibly a disclaimer about alkaline use).
I'm not an expert on battery voltages, but I believe good fresh alkalines are around 1.55v (maybe as high as 1.6?). I think they are pretty well spent (in just about any device) around 1.25v to 1.3v.
Time to hit the sack and later see what this thing's got for range tonight. If Foy is right and this thing puts a hurtin' on his 980L with throw, I may indeed forget about my woes quicker than I'd expect!
That light will not run well on alkalines with that driver and emitter. To be fair to Rusty though, the vendors ad does specify that it runs on alkalines. LED Flashlight-INTL Outdoor Store
Ok, I take back what I said about only being advertised for use with AA and not specifically alkalines. (Sorry, I should have checked the link myself first.) That is wrong to be advertised that way. Can someone who has good rapport with I-O-S (is it Hank?) email him and have him correct the listing?
Well... IMHO in a true emergency situation, I don't think one would need 6-700 Lumens at any given time. A more suitable light would be able to run lower output for longer run times, and I think 10-35 Lumens would be sufficient in most situations. So in that sense, a high output multi-AA light would not really benefit. So I think your light still could be used in lower modes with alkalines in an emergency situation. Unless of course even the low mode draws enough current to sag the alkalines and cause the EPROM to flip out.
I agree that the retailer should list the specifics and a disclaimer when using the various AA chemistries. I have seen other retailers do something similar. Furthermore I think they NEED to say 3x14500 (Li-Io) is not allowed... for safety and liability reasons.
I still think you should strongly consider going with Eneloops, they are AMAZING little power rockets. They reach something like ~3A (ballpark) without sag, and remain perfectly healthy while doing it. Charge em'... discharge em'... worry free. Imagine all the Lumens of a Lithium chemistry... without all the dangers, health risks and headaches? They are perfect for emergency situations too. They'll hold a charge for months (years), far better than Alkalines when you factor in how leak-prone alkalines can be. I have found my eneloops to be on par with my best Lithium-Ion cells in terms of LSD performers.
I come across as an Eneloop shill... but I am not. I have an over-whelming preference for 18650 and 26650. But in an emergency situation I know I can depend on my eneloop stash. My emergency-SHTF stash is mostly Fenix (MC-10, LD25, L1T, E21) they all run great with Eneloops, but the E21 is the only one that will work 100% with Alkaline.
I have several AA lights that seem to run just fine on Alkalines, including the TK41, my Caveman, and a few Klarus lights. But yeah, they aren't trying to put out 700 lumens...with the exception of the TK.
... and the brightest of those lights are probably series/parallel configuration. So the current draw is being split between multiple parallel banks. In the C88 each AA cell is going to try and pass ~3A on HI.
Hank has always been great about making quick changes to the website to add additional info, correct mistakes, etc. Rusty Joe, email him and I'm sure he will make the change if you ask him:
I'm just testing my Cyclone C88 NW with cheap IKEA alkalines and it "Seems to work"
TC currents are steady 0.11A on low and 0.68A on med. On high it starts from 2.20A, sags quite quickly to 2.00A and goes slowly down from that, BUT still stays on high and doesn't flicker.
I definitely got a dud then. Mine has just suddenly started cycling modes with mode memory working only occasionally. It started and then it stopped. Waiting for it to start again. I have the CW with disco modes and it keeps jumping back to strobe and SOS, and sometimes doesn't change modes when tapped at all. This can only be the reason you guys' "seems to work." This, in no usable sense, works. I'm sorry I got this. I hope Hank will make it right.