various bins
2025-08-04
- Type: multi die, flip chip
- Bin: various
- Color group: various (1800 - 6500 K
- CRI: 70
- Rated voltage: 2.6 - 3.2 V
- Max. Forward current: 9,000 mA
- Max. Peak current: — mA
- Viewing angle: 120 °
- Thermal resistance: 2.25 K/W
- Max. Temperature Tj: max. 150°C
Datasheet can be downloaded here: LHP531 (cool white only), 0.8 MB
This is probably the largest LED test ever conducted, with five CCT variants (1800, 3000, 4000, 5000 and 6500 K) of one single LED type tested simultaneously. In addition, the LED is disassembled and close-up images of the LED chip and substrate are shown.
The emitters tested here come from a Convoy order placed in mid-July 2025. Many thanks to German flashlight forum (TLF) user @J0hn for providing a large number of LEDs, which made this extensive test possible in the first place!
The LHP531 is a flat 5050 LED without a dome. Nine LED chips in a flip chip design are arranged in a 3x3 pattern on the ceramic substrate. The relatively close arrangement without clearly visible gaps should result in a good light pattern. A white, relatively stiff silicone compound has been poured around the phosphor-coated LED chips.
The footprint offers no special features. 5050 boards are fully compatible. The LHP531 can only be operated at 3 V; 6 V connection is not possible.
Depending on the CCT, there is a slightly yellowish border around the nine LED chips. As the CCT decreases, the phosphor becomes increasingly reddish in color. The light-emitting area is 13.5 mm² (1800K: 14.3 mm²).
- at 9,000 mA (official maximum current): 3298 lm @ 3.03 V
- Power at official maximum: 27.3 W
- Efficiency at 9,000 mA: 121 lm/W
- Maximum reached at 25.4 A, at this point 5952 lm @ 3.44 V
- Power at maximum 87.3 W
- Efficiency at maximum 68.2 lm/W
Data for 25 °C Tsp (at 85 °C the luminance values are around 13 % lower).
Due to the already extensive scope of testing, the LHP531 is only compared here in terms of its various CCTs. For comparisons with other LEDs, please refer to my existing tests. All in all, it offers high performance. It is interesting to note that the maximum current decreases with warmer CCTs. This is probably due to the increasingly thicker phosphor layer and the associated reduced heat dissipation.
Only the 1800 K variant stands out with a significantly lower luminous flux. Up to 3000 K, the LED offers a relatively constant high performance. However, it should be noted here that the LHP531 is currently only available in 70 CRI. If high CRI variants appear at some point, a significantly reduced performance is to be expected.
The specified flux bin is almost always missed. To the best of my knowledge and belief, measurement errors on my part can be ruled out, although I cannot guarantee this, as my measurements are always compared with (non-accredited) reference light sources. The 1800 K variant achieves the flux bin specified in the order code.
The forward voltages of all variants are very close to each other, which indicates precise binning of the chips. The 1800 K variant performs best in this respect.
The luminance decreases proportionally to the measured luminous flux with warmer CCT. The 6500 and 5000 K variants are certainly suitable for throwers, although single-die LEDs with a considerably smaller luminous area, such as the SFT-40 or SFT-25R, have a significantly higher luminance.
After the test, two LHP531s were damaged (3000 and 5000 K). After 15 minutes of operation at maximum possible operating current, black spots formed over the light-emitting surface. These are embedded in the silicone or phosphor and cannot be wiped off, even with alcohol.
Interestingly, these black spots did not grow larger after several hours at maximum possible current. However, operation with such (pre-existing) damage is not recommended in any way, as this can destroy the LED in a short time. Due to the seemingly random occurrence of such damage, contamination with some dirt/foreign particles in the phosphor or silicone is suspected, so that in principle any CCT could be affected.
Without the phosphor layer, the chips glow in the typical blue color (peak 450 nm).
The LHP531 is equipped with nine chips. These are said to have been manufactured by Sanan. An LHP531 6500 K was disassembled to obtain the detailed images.
The connection layout on the ceramic substrate is clearly designed for 9P configuration only. All chips are connected in parallel.
The beam in OP reflectors is excellent (pictured: 1800 K version in an OP reflector of a Convoy S2+). In SMO reflectors, depending on the geometry and focus, there may be minimal artifacts such as donut holes, but these are never distracting. This is generally more the case with cool white LEDs, as the phosphor layer is generally thinner with these CCTs and gaps between the LED chips are therefore more noticeable in the beam.
1800 K
3000 K
4000 K
5000 K
6500 K
1800 K with added cyan component:
The spectra themselves offer little surprise. The variants down to 3000 K offer the typical spectrum of a white LED with a very pronounced cyan hole and low red content. The color rendering index is therefore naturally low. Only YAG:Ce3+ and Ca-a-SiAlON:Eu2+ are used here in various emission peaks (for the neutral and warm white variants).
The 5000, 4000, and 3000 K variants offer a partly strong pink tint. The 6500 K variant is slightly above BBL. The dispersion of the color location is relatively low, but still present (only 5000 K variant tested, sample size n=5):
Sample No. / CCT, Ra/R9, duv
#1: 5429 K, 73/-25, -0.0044
#2: 5381 K, 73/-28, -0.0024
#3: 5260 K, 73/-30, -0.0023
#4: 5348 K, 72/-26, -0.0046
#5: 5373 K, 73/-29, -0.0024
The 1800 K variant, on the other hand, is interesting because, unlike the NTG35/FFL351A 1800 K, for example, it is not a classic full-spectrum LED. Instead, it corresponds very closely to PC Amber LEDs. These were primarily developed as a replacement for sodium vapor lamps. This means virtually no blue component and an emission peak at around 600 nm, which is generated almost exclusively by Ca-a-SiAlON:Eu2+.
The tint is very distinctly yellowish (positive duv), which is typical for PC amber LEDs; see also the test of an older XP-E2 PC Amber. Such LEDs are not suitable for ambient or mood lighting, as the colors are greatly distorted and the saturation is low. As soon as even a small amount of blue or even cyan is added (see spectrum), the CCT increases minimally, but the duv decreases significantly and the color rendering index increases significantly.
The LHP531 1800 K is therefore not suitable for normal lighting applications. For classic lighting tasks – especially in living spaces – full spectrum LEDs with the highest possible color rendering should always be used.
5000 K variant:
- Ra: 73
- R9: -25
- CCT: 5429 K
- duv: -0.0044
The LHP531 generally does almost everything right. Good beam (especially at warmer CCTs), good tint (as far as available in later batches), an extremely affordable price, and full compatibility with (even older) 5050 boards make it a good choice for retrofitting existing lights.
The biggest drawback is the unachieved flux bin and the 1800 K variant, which is not suitable for everyday lighting and also falls well short of its specified color rendering index due to the PC Amber spectrum. On the other hand, it is one of the very few PC Amber LEDs that achieve more than 1000 lm, making it particularly interesting for modernizing sodium vapor based street lights.
I also hope to see high CRI variants and a true full-spectrum 1800 K variant soon, which would significantly expand the range of applications once again.
Thank you for reading this test. 
To see x2 brightness we need x3-x4 more power. Running at 3amps we need to increase power to 12amps to see perceived x2 brightness.