SunLikeLamp.com sent me two of their warm LED bulb for testing.
Manufacturer website: SunLike3-5 светодиодная лампочка
The E27 bulb is the standard A19/A60 size. The candelabra version with the E14 base is quite long so it’s probably best suited for chandelier type fixtures.
The main specs by the manufacturer:
–2200K color temperature
-Chinese SOL COB LEDs
-CRI (Ra) 97
–4.4/5W power rating
-AC voltage of 85-285V, also available as a 3-35V DC version
-lifetime estimate 20 years
-warranty 11-22 months depending on payment method
Measurements
Measurements were made in a 50cm integrating sphere with an x-rite i1pro spectrometer after the bulbs had warmed up for 1 hour. Intensity (lux at 1 meter, candela) was measured outside the sphere at 50cm.
The bulbs were connected to mains power which at the time of testing was at 224V.
Output at 1 hour is 235 lumens at 4.3 watts for the E14 model and 310 lumens at 4.7 watts for the E27 model. Manufacturer doesn’t specify output.
Efficiency is mediocre even for a very warm and high CRI light source at 55 and 66 lumens per watt respectively. I was surprised about the efficiency difference between the lights, since they seem to share both the LED and driver topology. Maybe the peculiar candelabra optic isn’t as efficient as the plain diffused bulb. It does look like the optic opening isn’t perfectly suited for a larger COB led used in the bulb.
For all practical purposes maximum output is reached immediately. Light output in lumens was plotted over one hour. Output drops only a little during the first hour and doesn’t take long to plateau. Output is perfectly stable regardless of house AC voltage fluctuations.
Color rendering
The CRI data was measured integrated after a 1 hour warm-up in an integrating sphere.
E14 sample
E27 sample
Color rendering is good reaching CRI Ra of 97 and R9 of 88-94. TM-30-18 fidelity index Rf of 93 and gamut index Rg of 95 are good, but there’s some desaturation in the yellow and magenta. This doesn’t really matter as the 2200K LED doesn’t exactly pop out colors anyway. Visually the light has a very slight orange tint verified by the measured positive duv. The super low color temperature is good for sustaining melatonin levels at night.
Here is the color data when the bulbs are installed in a light fixture (Ikea Tertial) and measured directly below. Results are pretty much the same as when measured integrated in a sphere. One notable difference is the better R9 value on the E27. The E27 provides twice as much lux at a target at a similar power level than the E17 bulb in a real life situation.
E14
E27
Load IES TM-30-18 Color Rendition Reports by clicking the thumbnails:
CGATS CRI Data files:
E14 bulb: SunLike 3-5 2200K E14 LED bulb - Pastebin.com
E27 bulb: SunLike 3-5 2200K E27 LED bulb - Pastebin.com
Color temperature and tint
Tint is slightly above the black body line on both bulbs. Remember that when LEDs heat up, their duv value almost always decreases and becomes less green/yellow. This was measured after 1 hour in an integrating sphere when the output and tint were already stable.
Tint shift is not an issue on either of the bulbs.
Flicker
Flicker is not an issue. Slight ripple at ~90kHz and a snob index of 0% guarantees visually stable output.
AC power draw
Electrically both bulbs behave identically. Current is drawn in short pulses 100 times a second as the input voltage gets high. Power factor is low at 0.55-0.57.
E14
E27
Cyan line: mains line voltage
Yellow line: current draw of the bulb
Violet line: power draw (voltage * current)
Noise
Both bulbs emit a slight buzz. The E27 model was subjetively louder and was clearly audible at one meter. Installing the bulbs into a light fixture with a reflector (Ikea Tertial) amplified the noise.
Verdict
The Sunlike 3-5 2200K LED bulbs are very warm and cozy lights with a good color rendering for night time use. They will be good at sustaining melatonin levels and not messing your sleep cycle. Downside of super warm light and good color rendering is the low efficiency, but as these lights are probably meant for occasional use in small quantities, that shouldn’t really matter.
The one drawback is an audible buzz heard from both bulbs. It’s probably not an issue in an enclosed light fixture, but annoying if used close to the user as a bedtime reading lamp for example.
Please note that the test was done when the bulb was brand new. I can’t guarantee that they will perform similarly after months or years of use.