I have several other XML's and have been impressed with all of them but this thing just rocks
Are there any other single 18650 cell XML's that look as good as this thing? I don't think so!
The large diameter reflector and those chunky heatsink ribs should really lend itself to being pushed to the limit. If the stock driver is pushing anything less than 2.8A on high, I will be fitting a 3 mode, 2.8A (or more) driver.
Really looking forward to this beast arriving.
By the way, it is a little dissapointing that the bare X9 can only be purchased on ebay (@ ~$35). While KD & DX only offer the X9 package deal with the crappy charger and battery. I'm not saying that $45 for the package deal is bad value for money, but many of us already have enough 18650's and chargers and we really only want to purchase the flashlight.
Having said all that, if one of the vendors was to offer a 3 mode (H,M&L) version with a 3Amp driver, I would happily pay $45 just for the flashlight. Hint hint ....
That really indicates just how poor the driver must be in the X9.
The XML forward voltage specs indicate that it should draw 3 amps from a 3.35v supply!
The fact that your X9 is only drawing 0.91 Amps @ 3.57v shows how ineficient the X9 driver really is on a single 18650 cell. For an XML to only draw 0.91A, the votage getting to te emitter must be only 2.95V, so the driver in this case must be dropping 0.6v across it..
If you replace that driver with an 8x AMC7135, the XML should draw 2.8 Amps right down to 3.6v or close to the battery low voltage protection point.
I have never been a fan of dual voltage (3.7 & 7.2V) drivers. Seems very few manufacturers are able to produce a buck driver that works adequately on 7.2v and still provides good performance at 3.7v and this is just another case in point. Ditch the crap driver and X9 will really shine
That's the driver I've had bookmarked for an X9 mod, but now I'm confident that I'll do this. I'll get it ordered this weekend. Thanks!
Btw, have you already removed the pill and if so, how did you go about doing it? I've only unscrewed the emitter to take a peek at the top side of the driver.
I've only got some LG laptop cells, some UF 17670's and the blue UF's that came with the light.
However, I shudder at the thought of paying $20+ for one cell. lol Anything decent in the $10 range? I know that this will rule out AW, Callies, Redilast, bare Sanyos and Panic's.
I was really hoping the LG cells would work nicely as they didn't cost anything per se.
Check out the Hi-max 18650. They test out very well and are reasonable at about $7 each shipped or less. (The seller accepts offers of $5/each without issue and then you pay the shipping costs)
My X9 is pulling 0.8A on a freshly charged cell at 4.2V. I'm not sure if there is an issue with the leads because all I can verify that works correctly is testing voltage. It also only reads 1.3A for my L2i with a MF 3-mode drop-in. I'm getting a good connection with the body on both. Is there a problem with the DMM or could they both possibly be duds? I doubt the L2i's results because that thing is dang bright and will certainly get hot on high after a bit.
0.80A on HIGH
0.50A on MED
0.11A on LOW
These numbers are all reliable every time I test it and not on the same spot (threads) either.
EDIT: Now tested with the Equus 3320
1.85A on HIGH
1.00A on MED
0.20A on LOW
The DMM (or leads) do make a big difference and the Equus 3320 has proved to be far more consistent. In fact, I'll go as far as to say it's primarily the leads because I used the HF leads in the Equus and got similar results as I got with them plugged into the HF DMM.
I can't tell what gauge since I'm not sure of the casing thickness but they're about 3' in length. It's a cheapo Harbor Freight DMM. I suppose they work good for voltage but maybe aren't quite up to the task for amperage testing?
As I have mentioned before an XML emitter requires about 3.35v to be applied to it before it will draw 3A
or about 10 Watts. If the voltage across the emitter drops by only 100mV to 3.25V, the emitter will draw only
2.4A or 7.8 Watts.
Forget about the un-loaded battery terminal voltage of your freshly charged 18650 - It is meaningless!
All 18650 batteries (no matter what brand or how much you spend on them) will immediately start to drop the terminal voltage as soon as a load is placed them. Place a 3A load on a freshly charged 18650 and even the best 18650 cell (arguably the AW 2600's) will drop to 3.6V almost immediately and worse still, that voltage will keep dropping albeit at a slower rate..
The green line on the chart above represents the battery terminal voltage of an AW 2600 at 3amp draw.
The red line is at 1A draw and the black line is 0.3A draw.
(courtesy of 'HJK' at CPF).
The green line on the chart above represents the battery terminal voltage of a typical generic 18650 at 3amp draw. Notice the immediate drop to 3.4V at 3A load. This battery would be unsuitable for a single 18650 flashlight. Most 18650 batteries do not have a low enough internal resistance to handle a 3A load well. They might be fine for an XPG or R2 and 1-1.5A, but no good for an XML.. Again courtesy of 'HJK' at CPF.
You can see how important it is use good quality 18650 cells with low internal resistance and to mimimize driver and wiring losses with single cell XML lights. Even with the use of an 8x AMC7135 (regulated to 2.8A & 9.25W) and a AW 2600 battery, the driver could only regulate that output for about 15-20 minutes. After this point the battery terminal voltage will drop below the voltage required to maintain regulation and the output will start to dim gradually. Even after you loose regulation though, you should still have another 30-40 minutes of runtime at reduced output..
No problem bro, thanks for the detailed explanation, it'd be nice for the newbies.
Bro mitro did all the hardwork for us. The Sanyo 2600s have a really good knee. And even the TF flames 2400 are usable. You'd be happy to know after the XTAR promotion in July, a lot of us are operating on XTAR 2600s which are Sanyos. Bro picthris said correctly that these are "not good" because they are unable to provide a lot of current, he is somewhat correct....only in the sense that the PCB is tuned to cut out like 4.0A so not exactly suitable for the hardcore lights. I cannot run my DD triple XM-Ls with this at full charge, can only charge to say 4.0V and let it sag. But CNQG is selling Sanyo 2600 unprotected cells (be careful) for $5.50 ea. Great stuff/great price.
The Solarforce 2400 are pretty good stuff also. They just tail the XTAR 2600 a wee bit in all the run time tests in 2-cell regulated triple XM-L lights doing 2.5A starting and ending at about 3.6A, so that's pretty hard discharge. Eg 50 mins for Solarforce 2400, 54 mins for XTAR 2600.
Here's a zoomed in portion that we'd be interested in, approx 3.3V. But no worries, 3.2V loaded giving 2.4A is still plently bright. (if you don't put a meter on it, you'll never know)