Review: Ultrafire WF-502B with XP-G R5 drop-in

UltraFire WF-502B with 1-mode XP-G R5 drop-in

Reviewer's Overall Rating: ★★★★★

Summary:

Battery: 18650/2xCR123A
Switch: Reverse clicky
Modes: 1
LED Type: Cree XP-G R5
Lens: Glass
Tailstands: No
Price Payed: $17.24
From: DealExtreme

Pros:

  • Bright
  • Cheap
  • Good battery life
  • Looks good

Cons:

  • Rough threads
  • Not much heatsinking

Features / Value: ★★★★★

I have been looking for a light using a Cree XP-G for a while. I was able to resist the first round of XP-G lights from KaiDomain which turned out to have some problems with the LED set too far below the reflector. And I was able to resist the first round of DealExtreme lights including the Skyray and Uniquefire L2's (the L2 looks just like my Ultrafire WF-504B). But then DealExtreme introduced some older P60 hosts with XP-G drop-ins, including this 502B for only $17.24 which was less than $4 more than the drop-in by itself at $13.59. The drop-in was available in a 5-mode (with strobe and SOS and usually memory) as well as a 1-mode. The 502B with the 5-mode drop-in is $18.93, so I decided it would be a better value to get the 1-mode and order a 3-mode driver separately. From reviews posted so far the 5-mode driver has some problems.



I like that it comes with a clip instead of a lanyard. I don't know that the clip is that useful to me, but otherwise there is nothing to keep this light from rolling. Plus it looks good. However if you want a lanyard, there are no holes in the tail so it would probably have to be attached to the clip. The clip is mounted to the tube with screws so if you remove the clip the light won't be watertight.



The light does not tail stand, but it is nice that it doesn't have any sharp edges at the back either. The crenelated head works out fine. Not too aggressive to tear pockets, but it allows light to escape if it is head down.

Build Quality: ★☆☆

The 502B is only my second P60 host. My 504B is silver and I was very impressed with it. I ordered the 502B in black (partly because I don't like the glossy black that the 504B is offered in). It was smaller than I thought it would be, but it looks quite nice. The anodizing doesn't seem to have any flaws. The clip on the side is very sturdy, being held in place with two phillips head screws. I'm not sure if tapping those screws makes the light less water resistant or not, but they do go all the way through, including the top screw whose hole goes into the threads (but not the screw itself).

The reverse clicky switch is firm but the rubber boot itself is smooth instead of textured. It feels like it has been worn down. I like the textured one of the 504B better.



The body comes in 4 main pieces: the tail, body tube, throat, and head. There are o-rings in each location. The threads and o-rings came lubed, but they are rough. As I was cleaning off the lube and rubbing a rag along the threads with my thumbnail, the rag would tear. After working the threads taking the light apart over and over again, the threads were okay, but this was disappointing especially compared to the 504B which had very good threads right out of the bubblewrap. The o-rings themselves aren't all that tight against whatever screws in over them, but I don't doubt the light is watertight.

The lens seems well secured by an internal bezel (the 504B's is external) with an o-ring in front of the lens. The lens itself had a little dirt on it which was easy enough to remove once I unscrewed the internal bezel.

One of the biggest problems with this design is the throat is quite a bit larger than the P60 drop-in itself. The drop-in is about 22mm and the internal diameter of the throat is about 24mm, so there is a 1mm gap all around and the only way to transfer heat is where the reflector bears on the top of the throat. With the 504B the throat is only 22.5mm and I was able to cut out some strips from a soda can and get a snug fit. I wound up using 4 layers of strips in the 504B. But in this one, I needed more like 8 (I doubt the heat transfers as well with so many layers but I scrubbed most of the paint off the aluminum to help, and the light did get warm during the runtime test). Another possible solution would be to get some 1mm wire and wrap it around the drop-in, but I don't have any wire the right size (it would need to be 19 gauge wire which isn't a common size; on a trip to Home Depot I couldn't even find any 20 gauge wire that was solid copper). With the 8 strips, the fit was tight enough that I had to remove the Super Bright R5 label from the drop-in to slide it in place.



The drop-in itself seems pretty reasonable. There is a textured OP reflector and the opening in the reflector seems to be correctly sized for the XP-G LED instead of an XR-E which would have a bigger hole. A piece of thick paper is stuck over the emitter mounting board with a square hole for the XP-G shape. This is good as it allows the LED to get up into the reflector as far as possible. I didn't notice a speck of dirt on the dome until I was taking pictures and it brushed off no problem. Taking off the paper shield, the LED seems securely mounted to the pill, though you should be careful if you try this because the paper is very sticky and it seems to have been applied before the adhesive around the LED could set up.



The driver seems pretty decent as far as I can tell. It is on a red circuit board with a red ring on the bottom, which some people say indicates a better design than one that had a lot of failures. After writing the review, I replaced the board with a 3-mode, so here is a picture of the driver:

There were a few thin shards of metal in the head of the light, probably from the threads, that I removed. They were tiny, but they shouldn't have been there at all.

Overall, I can't complain too much about the quality of a $4 host.

Battery Life: ★★★★★

For the amount of light, the battery life is impressive. Maybe this is as it should be since the XR-E R2 has an efficacy of 104 lumens per watt while the XP-G R5 is 132 lumens per watt (based on Cree literature). So even though you are getting a lot more light, the LED is more efficient. The 1-mode driver is drawing more current, but it doesn't shorten life by that much, giving 90 minutes instead of the 105 minutes I got with the 5-mode R2 using the same battery. Based on the declining current draw, the light doesn't seem well-regulated and is probably direct driven (to some extent, because the light can take 2xCR123A, there must be some way of bucking the voltage).

Here's a group shot of the Fenix L1D, AKOray K-106, Ultrafire WF-504B, Ultrafire WF-502B, and Brinkmann 2xAA Minimag:


Time Volts Current (mA)
0:00 4.21 1480
0:15 4.00 1250
0:30 3.88 1150
0:45 3.81 1030
1:00 3.74 950
1:15 3.66 870
1:30 3.60 810

With the aluminum strips in the head, the light gets warm, but definitely not hot at all. After 20 minutes it is less warm. It should probably be getting hotter.

After writing this I did a more elaborate test of driver effficiency. I ran batteries down to 4 different voltages and then took a voltage and current measurement at the battery and then at the LED. Multiplying voltage and current gives power which I then used to calculate efficiency with some impressive results. It almost makes me think the light is in direct drive (there is a LOT of solder on the positive and negative pads and it looks like it spills to some other pads, which may not have been intentional; you can see this on the right edge of the driver in the picture above) except that I accidentally put the reflector in the light without an isolator disk over the LED and the light was in direct drive, drawing over 2 amps and only one mode. So if it were direct drive, the draw would be much higher.

At rest battery voltage 3.56 3.81 4.04 4.12
Battery voltage with load 3.46 3.72 3.89 3.97
Current draw at battery (mA) 610 840 1080 1100
Power in (watts) 2.11 3.12 4.20 4.37
Voltage drop across LED 3.04 3.09 3.11 3.11
Current drawn by LED (mA)
600 870 1110 1130
Power at LED (watts) 1.82 2.69 3.45 3.51
Efficiency Pout/Pin 86% 86% 82% 80%

The efficiency is very high. Another multi-mode driver I tested at the same time with this LED was in the 60's. The current to the LED is actually higher going in to the LED than what is drawn at the battery. But look how the power at the LED drops off sharply between 3.81 and 4.04 volts.

Light Output: ★★★★★

Finally! This light is quite bright, significantly brighter than the XR-E R2 drop-in I have. The R5 should give off about 22% more light than a R2, but the driver seems to be driving the LED pretty hard as well with the draw of 1.4A to start with (the R2 driver draws 1.2A). Some of the measurements on CPF indicate 300 lumens for the first few seconds before dropping off to around 270 lumens. That seems about right.

The tint is quite nice. The hot spot is very white, but the spill is a little bluish. The R2 has more of a violet or gray looking tint whereas this is just bright white.

After about 50 minutes it is less bright, but still brighter than my R2. Even at the end, with the battery at 3.6 volts and drawing 0.8A, the light is as bright as the R2 on a fresh battery. That's impressive.

The beam quality itself seems very good with a tight hotspot and a decent amount of spill. I was expecting the hotspot to be bigger and more washed out than the R2, but actually the intensity is quite good. Given the lack of rings, I wonder if a smooth reflector wouldn't do this LED more justice.

XP-G on the left, XR-E on the right at 1/25th second:

at 1/200th second

at 1/1600th second. The P60 reflector does a nice job of focusing the hotspot, but you can see it is still bigger and it also seems more intense.

The last picture is at 1/200th second with the 502B on a low battery (3.63V) and the 504B on a fresh battery (4.20V). They light is about the same, but the 502B might have the edge since it has a bigger hotspot.

Out on the backyard range, the 502B outperforms again. For comparison, here is the 504B with the XR-E R2. This light throws its little hotspot pretty far, so notice how the fence posts are illuminated. They are about 120' away. The stick in the ground is 25' away. This is a 4 second exposure:

Now here is the 502B. You can see there is more flood, but the throw is also better. There's just a lot more light:

Now for one more comparison, here is my Ultrafire MCU WF-1200L with P7 emitter, running off of 2x18650 batteries. This light has a big reflector for better throw and puts out at least 400 lumens:

To compare the throw, here is a zoom-in of the fence posts for all three (504B R2, 502B R5, and 1200L P7):

Summary: ★★★★★

This is a pretty solid light and a very good value. If you want a 1-mode light, this one is great (though the Seraph clones or Uniquefire L2 hosts are better quality for only a few dollars more). But because the light is so bright, I do think lower modes are needed. Then the problem is finding a good driver for it. I will try the NANJG AK47 driver and see how that goes. I may also try to measure the current to the LED at some point.

I didn't realise the XP-Gs were that efficient though I'd guess that was at a much lower drive current than 1.4A - they usually seem to measure the efficiency at 350mA or less. Not that I'll ever know as you'd need to spend tens of thousands on lab gear to test this properly. I seem to remember around 80-90 lumens/watt when hard driven but my memory may well be at fault like when trying to remember which Cree LEDs have the ring.

Those efficacies are at 350mA (only 139 lumens at the emitter for the R5) so they would be less at anything useful like 1000mA. The new XM series is supposed to be 160 lumens per watt and Cree has a press release saying they have attained 200 lumens/watt in their lab with non-production LED's.

Especially as the XMs can be driven at 2A for silly lumens. Just happily awaiting my 23 minute runtime (With 5000mAh cells) SST-90 light now estimated as up to 3K lumens. Efficient no, bright definitely. At the theoretical maximum this would be a 12,000 lumen light!

The theoretical limit is about 400 lumens/watt so hopefully we'll be seeing a lot more light for the same current for some years yet. I believe Nichia has some 5mm LEDs that can do over 200 lumens/watt but then they only use fractions of a watt at best so aren't the sort of things I'm looking for - they aren't about to give me the sun in my hands.

Awesome review, that sucker is bright. As for the tailcap is it the standard size like all the other lights we have.....if you need some i can send you a couple of black and orange textured ones.

If you're interested in light output at high currents, you can calculate the theoretical lumen output at various currents for most of the LEDs from the spec sheets. Someone at DX did it http://www.dealextreme.com/forums/Forums.dx/Forum.-209~threadid.530221

I tried a few myself and results seem the same.

BTW the XM-L is is supposed to put out 750 lumens at 2A! (Yes this isn't that far from the highest binned MC-E or P7 at the max spec 2.8A.) Although I would take a guess this is the top bound of the highest bin at release, i.e. the actual bin will be something like 680-750 lumens at 2A (still 2A for 680-750 lumens vs 2.8A for 800-900/753-858 lumens). If you haven't seen it there's now also a slide from Cree's presentation at Light Fair on the XM-L that may be of interest http://ledinside.com/News_cree_LED_20100513

Thanks for posting that, made a good read def.Cool

It sounds like the XM LEDs won't really be suitable for flashlight use. Pity...

Oooops, this review escaped me until now. Sorry about that brted! Wonderful high-quality review as usual. Now frontpage'd and sticky'd. I also played with physics and changed the date you published the review so that it goes to the top of the frontpage. ;)

Thanks for making it a sticky!

As a follow-up, I did replace the driver with the NANJG AK47, which I reviewed here:

http://budgetlightforum.cz.cc/node/310

The bottom line is that the new driver doesn't ever draw 1.4A like the original did (sometimes), but it is much better regulated and maintains that 1.05A draw down to about 3.8V. Also I like the 3 modes. I also replaced the smooth black tailcap with an orange one with some texture. So it was pretty easy and cheap to get rid of a few of the cons about this light and it is still very bright.

I got the 5 mode version of this from KD. There's only 1 board inside with what looks to be 1 mcu chip, and the current draw (>2a at start) implies it's just direct drive with a mode circuit. The soldering is also pretty crap (driver fell out), and the thermal compound never vulcanized properly or something so the emitter pcb falls out too if you take the reflector off. The 502b is pretty nice, though.

So.... get the 1 mode from dx and avoid the 5 mode KD if you really want to take the chance.

Sorry to hear about yours. I hope you were able to get your fixed up (or return it). After KD's early R5 drop-ins seemed to have the LED well behind the bottom of the reflector, I was afraid to get one from them. Is/was your LED partially blocked by the reflector?

I still really like my 502B with the 3-mode NANJG AK-47 driver in it. I also replaced the smooth black switch cover with a textured orange one and I think it looks great.

Is/was your LED partially blocked by the reflector?

It kind of looks like it, but not really. It's a proper xp-* reflector. The spot is well formed so that's hardly the problem with it....

I do quite like the 502. Kind of has that industrial feel of socialism to it :)

Great deal for ultrafire WF-502B

http://budgetlightforum.cz.cc/node/1228

Ultrafire WF-502B Cree XM-L U2 And UltraFire WF-502B Cree XM-L T6 ,

so than Cree XP-G R5. what better.

I imagine the 5 mode drill is same as my WF501s. Don’t have my 502 yet, but I don’t think I like clips. Maybe just remove it and replace the screws with a little CA to seal. Shorten the screws? Otherwise the light looks good for 11 bucks with a long delivery wait.

Jaxon

Hi Guys,

do u know if this Light is original or no? The price is good

Many thanks

Ale

Have a pleasant time here at this friendly forum, robbynaish!

Looks just like mine. Also looks like a good deal!

@raccoon city

Thans for your welcome message

@JaffoAZ

Thanks, i will buy in that shop… hoping yr comparison is right :slight_smile:

Alex