A Leslie Wong Blog

I’m a big fan of Cree LEDs. I use them in almost all my flashlights. Last month, a Cree LED light bulb was introduced that replaces a 60 watt incandescent bulb. (Cree Press Release) The bulb retails for $12.97.

Specifications from Cree:

*Cree’s calculation of $1.14 yearly operating cost is based on 3 hours/day and $0.11 per kWh. Cree’s lifetime savings calculation is based on $0.11 per kWh when compared to 60W incandescent and 25,000 hour lifetime.

It seems that the Cree LED Light Bulb is only available so far from Home Depot. I bought my bulb online from Home Depot and with $1.17 sales tax and $5.99 shipping, the total was $20.13. When I first removed the bulb from the packaging, I was surprised that the light bulb’s envelope felt like it had a rubber coating. It has a standard North American Edison screw E26 socket. I replaced a 15W warm compact fluorescent bulb (CFL) that was in a table lamp with the Cree LED Light Bulb. The LED seems brighter.

When I removed the lamp shade to photograph the bulb, I noticed that the bulb was hot enough so that I couldn’t hold it – so despite consuming only 9.5 watts, it still gets very hot. There is a heat sink around the base of the envelope.

When I photographed the illuminated bulb, I set the camera’s color balance for daylight, so the yellow color of the light reflecting off the wall in the background is a good representation of what it looks like to the human eye.

For the chart below I used the following cost assumptions:
Incandescent bulbs: GE 60-Watt Reveal A19 General Purpose Incandescent Light Bulb (6-Pack) $8.77 ($1.46/bulb, 1000 hour life)

CFL bulbs: Feit Electric 15 Watt ( Mini Twist Dimmable Light Bulb (12-Pack) $104 ($8.67/bulb, 8,000 hour life)

LED bulb: Cree 9.5-Watt A19 Warm White (2700K) LED Light Bulb (1-Pack) ($12.97 25,000 hour life)

Cost of electricity from PG&E, about $0.13/kWh.

To get 25,000 hours with a 60 watt incandescent bulb, you would need 25 of them, at a cost of $36.50. The cost of 4 CFL bulbs for 25,000 is $34.68. The cost of the Cree LED bulb for 25,000 hours is $12.97.

There’s no question about the cost savings of the LED bulb versus incandescent. Total cost for 60 watt incandescent bulbs for 25,000 hours is $231.50. Total cost for 15 watt CFL bulbs for 25,000 hours is $83.43. Total cost for a 9.5 watt LED bulb for 25,000 hours is $43.85.

People who want to keep using incandescent bulbs may not be able to do the math or maybe they’re using them to keep their popcorn warm.

View slideshow on Flickr

I bought a Surefire E2E because it was a good deal. I didn’t realize until I received it how much smaller it is in comparison to the Surefire 6P flashlights that I have. It’s about the same size as my JETBeam Jet-I Pro.

The E2E uses an incandescent lamp, the Surefire MN03 lamp assembly, with an output is 60 lumens. The output seemed a little low so I started looking for ways to make it brighter.

Fivemega, over at candlepowerforums.com makes two nice incandescent options for the E2E, a bi-pin socket and a Mini Turbo Head.

I’d rather use LEDs and I found that Veleno Designs makes a good option fits in the E2E head. The Veleno Designs E Series LED drop-in is machined from brass, has great heat sinking and uses a Cree XP-G LED. I ordered a 3 mode cool white model and while the output was great, the tint was a little green. The manufacturer said that most people order a neutral tint so they don’t have that problem.

I decided to order some neutral tint Cree XP-G LEDs from DigiKey to replace the LED. After I soldered the LED to the board, I trimmed the board with a Dremel so it was a little larger than 3.5mm x 3.5mm, so it would fit on the Veleno pedestal. It still had a green tint.

In a few discussions on cpfmarketplace.com, it was theorized that the E2E reflector was causing the green tint and it was a lottery whether the factory reflector had the green tint. Instead of buying a new bezel/reflector, I tried re-silvering the reflector. The tint was still green.

Because of the work involved in putting another LED on the Veleno drop-in, I decided to try to find a deal on a Surefire KX2 LED Conversion Head. When I received it after a week, the tint on my new KX2 was also green. I had also taken a very long way to get to a E2L Outdoorsman.

Determined to get the light I wanted, I disassembled the KX2 using a heat gun to release the ample amount of glue that Surefire used on the threads to hold the head together. I unsoldered the leads from the LED board, removed the two hex screws holding the LED board to the drop-in and pushed the LED board out.

I then unsoldered the old Cree XR-E and reflowed soldered in a new Cree XR-E (R2 bin). I reassembled the KX2 using Arctic Silver 5 Thermal Compound underneath the LED board and when I first tried the light the hot spot was off center. I centered the LED and because the threads on the bezel that holds the Surefire Total Internal Reflection (TIR) lens were no longer glued, I was able to focus the beam to a perfect hot spot. And finally I have a neutral tint.

Now that the KX2 is open, I could use another driver, maybe try a McR-19XR reflector or an XP-G LED; but it’s been a long road to get here, so maybe I’ll wait a while.

A year ago I saw this Youtube video where Steve Dahl at DigiKey demonstrates a method of soldering high-brightness LEDs to a Metal Core Printed Circuit Board (MCPCB) using a heat gun.

Though I’ve seen an electric skillet used for reflow soldering, I decided to try using the above technique when I wanted to replace an LED on a drop-in. I ordered some neutral Cree XP-G LEDs from DigiKey, some 16mm circuit boards and some LodeStar solder paste.

I don’t have an expensive heat gun – just one for removing paint. I thought if I used my infrared thermometer, I could measure the temperature at the tip of the gun and when it was maintaining the correct temperature, I would hold the board/LED in the heat.

I put dabs of solder paste on the contact pads where the LED would be soldered and placed the LED on the pad. It doesn’t need to be precise because the solder will only flow onto the contact pads.

The Cree XP-G specs (PDF) have 215 degrees C (~419 degrees F) for Peak/Classification temperature. When my thermometer read that, I put the board in the heat. (In the video, they use 600 degrees, which seems way out of spec and may be the reason the board turned brown). In a few seconds the paste melted and the LED centered itself, just like in the video. I immediately turned the heat off and kept the fan running to cool the board.

In the photo, the bottom board has been soldered. The upper left board shows the amount of paste I used. The upper right board has the LED on it before soldering.

In late 2007, I bought a couple of Ultrafire C2 flashlights. They were nicely made for an inexpensive flashlight and they used Cree XR-E LEDs (P4 bin).

Last fall, I modded one of my C2s with a Seoul Semiconductors Z-Power LED P7. The P7 is a quad die LED. I made it direct drive running off a single Li-Ion 18650 battery. There were mods that could be made for a circuit board to drive the P7 but I was too lazy to make one.

I recently found a 3-Mode Regulated Circuit Board for Cree MC-E and SSC P7 LEDs (SKU 1217) sold by Shiningbeam.com that advertises an output current of 2500 mA on high. It has only three modes: high, medium and low. The 17mm diameter of the board is a direct fit in many pills, including a lot of P60s and the Ultrafire C2. I used one of the boards to improve a DealExtreme P60 MC-E drop-in.

I had another of the Shiningbeam boards and a quad die Cree MC-E LED, so I decided to put them in my other Ultrafire C2.

I soldered the LED to a trimmed down DealExtreme Star Connection and Heatsink for Cree MC-E LED Emitters – Parallel (SKU 16545). I’m not sure why they call it a parallel board, because each die is separately addressable with the connections on the board. I soldered all the anodes together and all the cathodes together, so it would run in parallel.

With a fully charged Li-Ion 2400 mAh battery, I measured the current at a little over 2700 mA through the tailcap. After five minutes, the flashlight was hot, but not so hot that I couldn’t touch it. It also dimmed slightly from initial turn-on but it is still brighter than my P60 MC-E mod.

With a McClicky switch in the tailcap, this is a really nice, bright flashlight now.

The current high lumen output LEDs use multiple chips on a single die. The Seoul Semiconductor Z-Power LED P7 and the Cree XLamp® MC-E LED are two examples that are in popular use by flashlight modders.

I recently bought a DealExtreme Cree MC-E LED 3-Mode Drop-in Module ($18.30 USD) for my Surefire 6P flashlight (the 6P body is bored to work with a single 18650 battery).

The DealExtreme P60 size drop-in works with 2.7V~4.2V – a single Li-Ion 18650 battery, single RCR123A battery or CR123A battery. There is also a not too low level mode and annoying strobe mode. In the Surefire 6P host (about 5.2″ long – 13.2 cm), the DealExtreme Cree MC-E drop-in is an extremely bright flashlight in a small package. There is an extensive list of similar sized flashlights that use P60 size drop-ins in this Candlepowerforums.com thread.

DealExtreme seems optimistic in their description of the MC-E drop-in brightness as 410 lumens. It has more flood and less of a hot spot than the Malkoff M30. For comparison, my Malkoff Devices M30 output is rated at a realistic 235 lumens. My SSC P7 mod, inspired by jirik_cz, gives me the feeling that I am seeing everything. If not for the $125 USD cost, I would be all over the Malkoff M60 MC-E (NLA).

In my flickr set below, there are beamshots comparing the Cree MC-E, Cree XR-E and SSC P7. I centered the beam of each light on the scrawny tree against the fence.

My latest flashlight is the JETBeam Jet-I Pro I.B.S. V1. It uses a single AA size battery to power a Cree XR-E 7090 LED (Q5 bin). The JETBeam Jet-I Pro I.B.S. came with a lanyard, removable clip, spare tail cap, two spare o-rings and a warranty card.

BugOutGearUSA.com, where I purchased my Jet-I Pro I.B.S. for $64.95 USD, now lists a Jet-I Pro I.B.S. 2.0. From what I’ve read, the 2.0 is only cosmetically different.

According to JETBeam specs, the lens is sapphire crystal and the body is T6061 T6 aluminum with a type III hard anodized finish. The dimensions: Bezel diameter – 25mm, Tail diameter – 19mm, Overall length – 100mm, while the weight is 50g.

The push button tail cap switch is a “reverse” click type, i.e., the switch will make or break contact after it clicks. I prefer the “tactical” or forward click switch – a forward click switch will allow a half press of the switch to turn on a flashlight.

I tried fitting two forward click switches – one that I removed from my LumaPower D-Mini Digital and a McClicky switch. Neither fit. Unable to find a forward click switch, I settled for replacing the black tail cap with a glow-in-the-dark silicone tail cap.

Because the Jet-I Pro flashlight will accept an input voltage of up to 4.2V, it can use a rechargeable 3.7V 14500 Lithium battery. The Lithium battery gives a not insignificant 100 more lumens when compared to a 1.5V Alkaline AA battery or a 1.2V rechargeable NiMH.

The main attraction of the Jet-I Pro is the I.B.S. (Infinite Brightness Setting) technology. The I.B.S. circuit allows for three operating modes, A, B and C, each of which can be set at any output of ~2 to 225 lumens. Any mode can also be set to one of five strobe modes including 1Hz to 15Hz, warning signal, standby (flash once every 8 seconds), 100% SOS and 5% SOS.

When reading about programming the flashlight, it seems complicated. In practice, it’s relatively simple. BugOutGearUSA.com has a page with the Jetbeam I.B.S. User Interface Instructions.

Output & Runtime (from JETBeam):

AA Battery
Max Output: 130 Lumens, lasting for one hour;
High Output (Default Mode A): 110 Lumens, lasting for 75 min;
Low Output (Default Mode B): 20 Lumens, lasting for 3.5 hours;
Minimum Output: 2 Lumens, lasting for 45 hours;

Rechargeable lithium Battery
Max output: 225 lumens, lasting for half an hour;
High output (Default Mode A) 180 lumens, lasting for 45 min;
Low output (Default Mode B) 20 lumens, lasting for 8 hours;
Minimum Output: 2 lumens, lasting for 50 hours;

Compared to my modded LumaPower D-Mini Digital (Cree Q5, DX 7612, single RCR123 and McClicky) the Jet-I Pro wasn’t as bright. But the D-Mini’s reflector is smooth, is deeper and 50% larger in diameter. The JETBeam Jet-I Pro I.B.S. is a great flashlight for its size and versatility.

I bought a Surefire 6P to house my Malkoff Devices M60 drop-in. You have to be kind of a flashaholic to understand that sentence.

Surefire describes the 6P as a “Compact (pocket sized), high-intensity incandescent flashlight for tactical, self-defense, and general use. (It) produces a smooth, brilliant, pre-focused tactical-level beam with three times the light of a big two-D-cell flashlight.”

The 6P’s stock lamp assembly is a P60 incandescent lamp. You can stop right there and you have a great flashlight that puts out 65 lumens.

The Malkoff Devices M60 drop-in (now replaced by the M61 with a Cree XP-G) uses a Cree XLamp XR-E LED (Q5 bin) as a replacement for the incandescent lamp. In addition to being more rugged, it puts out 235+ lumens. Gene Malkoff, the creator of the M60 says, “It will easily illuminate objects at 350+ feet and will blind opponents within a 100 foot radius.” That’s what we want.

Naturally, when I get something new, I take it apart and think about how to mod it. My new Surefire’s switch seemed like a good candidate.

The Surefire Z41 tailcap is standard on the 6P. It has a momentary option by pushing the tailcap switch. Rotating the tailcap will turn on the light for constant operation.

Most of my flashlights use a forward clicky switch. A slight press of the switch (before it clicks), will momentarily turn on the light and a full press (when the switch clicks), will latch it on. I’ve put the McClicky switch in seven or eight of my flashlights and thought it would work well in the Surefire 6P. I could have bought a Surefire Z59 Click-on Tailcap Switch or the Oveready McClicky Kit for USD $22, but it’s more satisfying making my own.

I yanked out the insides of the existing switch and unscrewed the retaining ring. Sometimes the retaining ring is glued. I’ve put the tailcap in a ziplock bag and boiled it hot water for five minutes and the glue will release.

Since I only had a plastic retaining ring to hold in the new switch, I soldered a piece of brass to the McClicky switch so that it contacts the inside of the switch housing. I put a dab of solder on the contact on the other side so the retaining ring would seat the switch flat inside the tailcap.

If you have an aluminum or brass retaining ring, there is no need to solder a tab – just screw it in. You must be careful about the inner part of the retaining ring contacting the positive connection on the raised plastic below the contact spring – it will short out the switch and be “on” all the time. A piece of shrink tubing or electrical tape wrapped around it will prevent a short.

Using that piece of brass also meant I had to remove the anodizing from the inside of the housing so the brass tab makes electrical contact with the side of the tailcap. With one mod that I did, I lost the lock out function, which “prevents accidental activation of light during tactical engagements, transportation, or storage,” according to Surefire. On another mod, the lock out still worked. In my case, I’m very unlikely to have a tactical engagement, so I can remove the batteries for transportation and storage.

To bottom it off, I replaced the black rubber push button cover with a Glow-in-the-Dark Silicone Tailcap…maybe a not too tactical feature.