The Cree 65W-equivalent BR30 LED flood light is based on many of the same components as its sibling product line, Cree’s 60W-equivalent A19 bulb. So it’s not too surprising that the flood light bulb has a similar performance: Its light quality CRI number of 80 and its color temperature of 2700 — both the same numbers as the A19 bulb — seem to be the default color quality and temperature for high-volume consumer LED light products.
At $20 per flood light, Cree realizes that many folks won’t want to go out and replace all of their incandescent flood lights en masse, but rather go one at a time as they burn out. Having a light which is noticeably different from neighboring traditional lights would be visually distracting, and it looks like these color-quality and -temperature numbers will let the lights blend in with archaic incandescent flood lights before eventually replacing them.
Incandescent flood lights are quite cheap: You can buy a 12-pack of Philips BR30 incandescent bulbs for just $28.47. However, Philips estimates the lifetime of these bulbs at 1.8 years with just 3 hours of daily use. Since they usually go into a recessed or track fixture on the ceiling, replacing them can be a nuisance and/or expensive. Cree’s LED floods, on the other hand come with a 10-year warranty that assumes 6 hours of daily use. And that’s just the warranty – if we’re going to compare apples to apples, Cree estimates the lifetime of the bulb at 22.8 years at 3 hours of daily use.
The bulb dimmed fine. I was able to get an almost imperceptible flicker when I took it down to the lowest setting on the Lutron Maestro programmable dimmer switch. (I had to really work to find this spot and see it.)
Several readers disagreed with me when I said there was no hum on the Cree A19 bulb, so I spent a lot of time and tried several fixtures with this flood. What I found is that the fixture itself plays a big part. How solidly the light holder is attached to the fixture can make the difference between something you’ll strain to hear with your ear 9 inches from the bulb and something that you can hear from several feet away. So the fixture may be the culprit if you experience an audible hum with these Cree bulbs. Granted, I have only one sample of this new flood light.
As usual, I soaked the bulb in the oven to the usual 200 deg F, gripped the bulb cover and twisted it off: It was attached with an adhesive.
The entire outside of the bulb cover (which is glass) is coated in silicone, apparently a UL requirement, and which leaves the broad dome top of the cover opaque. On the inside of the bulb cover is a white reflective coating that goes from the bottom up to the widest part of the bulb. This is a tough coating that is indistinguishable from the glass itself. On top of this reflective coating — but only about 3/4 of the way down — is a thick latex-like paint that seems to be hand-applied. We’ll return to this coating later.
Just like its sibling the A19 bulb, the array of LEDs is mounted on a 10-sided metal column. To compare, here’s the flood light LEDs on their column:
…and here’s the A19 bulb’s:
…and side-by-side, with the BR30 on the right. Note the slightly larger heat sink of the BR30.
The basic design is very similar, and relies on a metal-core pc board with the 10 LEDs mounted on it that’s folded into a decagon which in turn slips over the heat-sinking metal column. There are two significant differences: The LEDs themselves, and the reflector column below them. Let’s look at the LEDs first.
These ten LED that produce the bulb’s 650 lumens look like they are the Cree XLamp XB-E high-voltage white LEDs. These LEDs are packaged groups of 8 LED chips, with a total forward voltage of 23 typ/25max volts per package, which matches with the 223Vdc I measured across the string of 10 LED packages, indicating each LED package was dropping about 22V.
A feature of the XB-E package that makes it a good choice for an omni-directional bulb like this flood light is that much of the XB-E’s light exits through the edge of the package. Here you can see a close-up of the LED packages: Instead of the domed lens onto of a dollop of yellow phosphor, these packages have a flat, square clear lens that sits on top of the phosphor.
The mechanical layout optimizes this feature further by mounting the 10 LEDs in a diamond position with a corner rather than a side pointing up/down. Which brings us to the white reflector collar mounted below the array.
You can see that the collar (in the lower left) has a shiny, angled surface. As the light exits at the edge of the LEDs, it bounces off the collar surface and goes out the top of the bulb. Since the LEDs are mounted in that diamond pattern, more of the two sides’ light hits the reflector than if just a single flat surface faced the reflector.The light that exits perpendicular to the LED surface hits the white reflective surface on the angled sides of the bulb and exits out the top. Because of the all the reflections going on here, the bulb will produce a flood of light rather than a spot light beam.
So what about that white goop in the inside of the bulb? As you can see here, with the LED column removed, the LEDs and their collar are just about in line with the end of the goop, so the goop doesn’t have the do much reflection: The collar prevent the light from making it down there.
I have no idea what function the thick white surface performs. More protection in case of breakage? Some sort of heat transfer? Dunno.
On to the electronics
The bulb is non-isolated. (I’ve written about the significance of non-isolated power drivers in LEDs and safety issues elsewhere.) It uses the clever snap-together assembly I covered in the A19 tear-down.
I was surprised to find that this bulb is potted: The A19 was not. This could have been done for better heat transfer, or perhaps to further minimize vibration and noise. I had measured the bulb’s external temperature with an IR gun when I was testing the dimming and the hottest I measured, at the heat sink while in an inverted position, was 114F.
Digging into the potting compound, the power management IC is now the STMicro L6562A; The A19 bulb used the L6561.
The STMicro website says the 6562 is pin-for-pin compatible with the 6561, offering “improved performance.” The data sheet calls out, “The highly linear multiplier includes a special circuit, able to reduce AC input current distortion, that allows wide-range-mains operation with an extremely low THD, even over a large load range.”
In summary: Again, a very nice bulb from Cree, and one that should help further the advance of LED lights into the consumer market. The BR30 flood light is the second-most popular consumer bulb after the A19 size, but LED versions face different challenges in this market. First and foremost is that there is no government mandate driving incandescent bulbs out of the flood light market as there is in the A19 space. However, having to replace a ceiling-mounted incandescent bulb every year and a half is a definite drawback for incandescents. And the difference in your energy bill is significant: $7.83 for an incandescent flood vs. $1.14 for the 9.5W LED version. The energy savings likewise are significant in the A19 LED market, but CFLs are an alternative technology. However, CFL replacement bulbs are not as price-competitive in flood lights as they are in the A19 space: A dimmable CFL flood light from Philips costs $9.98 and gets bad reviews for its dimming. (The CFL version requires 16W vs the Cree’s 9.5W.)
The Cree’s price at $19.97 (Home Depot, exclusive) is not as significant a difference as it is in the A19 space: While $14 for a dimmable A19 60W replacement is a strong price leader, Feit has a dimmable LED BR30 for $19.97. And Philips has one for $24.97. However, neither of these has a 10-year warranty, and both are a heavier design with quite a bit of metal. Consumers will probably prefer the Cree.