Fake “SUNmini UVLED Nail Lamp”

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I have experienced that we have on eBay a new China-Seller-Scam in progress. There are right now many seller who sell Fake “SUNmini UVLED Nail Lamps”. This lamps do not have the power or the durability of the original Lamp (SUNmini UV Nail Lamp” from SODIAL  [basically the 2nd version of this lamps, this lamp is collapsible]).

I am writing this text because many women buy this product, most of whom are not electrical engineers and therefore cannot judge what they have in front of them. (simply as a help)


My initial experiences

In December 2018 I did need an UV-LED Lamp for hardening some type of UV-Gel and so I had found a very inexpensive and reliable Lamp for 3.68€ on eBay.

Original_UVLED_Nail_Lamp_from_eBay

Professional LED UV Nail Dryer Gel Polish Lamp Light Curing Manicure Machine 6W
Price:
US $4.39  (EUR 3,68)
Shipping:                  Free Shipping — Economy International Shipping
Model:
6W White Nail Dryer

At a test the output-power was not so high as it was advertised, only 4.3 Watt (not 6W) with my best USB-Cable, but it was doing the job and as I looked inside and did see a aluminium PCB for the cooling of the LEDs, I was happy with the whole product.

Positiv:

If you look into a UV-Lamp it could damage your eyes, but these LED chips have a silicone lens, which is mixed with some phosphorus, so that the UV rays are converted to a small extent to white light.

The eye recognizes the white light, so that the eyelid reflex is activated. 🙂


My new experience

At February 28, 2020 I did need more of the “SUNmini UVLED Nail Lamps”, so I did buy some of this lamps on eBay. Not from the previous seller (he did not sell this lamps any more), but from two other seller for nearly the same price with the same description on their eBay-product-website.

eBay-Fake-UVLED-Nail-Lamp_seller1

I got this lamps very late, because of the “Corona pandemic in China”, but  the lamps are looking exactly like my original lamp … except the printing on the surface. The text was the same, but the style was different.

Fake_UVLED_Nail_Lamp_from_eBay_with_Pakage

So I compare my original Lamp with the new one:

Original SUNmini “UVLED Nail Lamp”
Power: 4.3W (depends a bit on the USB cable)
Wight: 49.4g (without cable)
Upper shell: 13.6g
Lower shell: ? (I do not want to brake it apart)
Circuit board: ? (I do not want to brake it apart)
Lower shell + circuit board: 36.0g

Fake SUNmini “UVLED Nail Lamp”
Power: 2.5W (depends a bit on the USB cable)
Wight: 50.9g (without cable)
Upper shell: 15.8g
Lower shell: 26.6g
Circuit board: 9.2g
Lower shell + circuit board: 35.1g

 

Lets take a look on the printings

Vergleich_Original_und_Fake_TOP

A closer look:Vergleich_Original_und_Fake_Text_housingIt looks different, the fake does not have the line under the product-name and the printing is thicker.

De-assembling

It is very easy to open this lamp undamaged. Slits can be seen on the sides, which can be pushed apart a little with a knife. The best way to open the lamp is on one of the shorter sides, where the click lock is located.

Take a look at the housing from inside of the Lamp:

Vergleich_Original_und_Fake_TOP_inside.It looks almost the same. The weight of the upper shell is higher for the fake lamp.

Compare the LEDs:

Compare_Original_und_Fake_SUNmini_UVLED_Nail_Lamp_Bottom

… this is bad!

The LED-Chips are much smaller than the Chips in the original UV-LED-Lamp.

A closer look at this Chips:

Her is the original LED with the two chips inside, one is a 365nm UV-chip and the other a 405nm UV-Chip.

Vergleich_Original_und_Fake_LEDChips_of_the_Original

Compare the chips from the new Fake-UV-LED Lamp:

Vergleich_Original_und_Fake_LEDChips_of_the_Fake_2Vergleich_Original_und_Fake_LEDChips_of_the_Fake

These chips in the fake-Lamp are far smaller, even with the magnification of the silicone.

Compare the bottom-side of the housing:

Compare the PCB inside of the UV-LED-Lamp:

 

The original Lamp is equipped with a little driver-PCB for the USB-Connector, the switch, a MosFET and a little unlabelled microcontroller. The surface of the controller is sanded down, so that there is no dot-marking for Pin #1 visible. Behind the switch and the USB-connector was added a bit silicon, possibly for stability reasons.

The LED-Chips are soldered on a aluminium-printed circuit board (PCB).

 

The fake Lamp has nearly the same setup, but there is a little bit of thermal paste over the 1 Ohm resistor (right over the USB-connector) what do not makes any sense. It is pretty useless.

The LED-Chips are soldered on a FR4-printed circuit board (PCB made from “glass fiber and epoxy”). This means that the heat resistance is very high and the cooling is much worse.

 

There are several problems with this device in this condition.

1. The timer have the wrong time, because of the lower power the device need more time to harden the UV-Gel. It needs 2.4 times longer for the same work, but only if the LED have the same ability.

2. The ability will be reduced because of the overheating of the single LED-Chips, the Output-Power-Effiziency of the LEDs are lower if the temperature is increasing. Because this we have the problem of increasing duration of time. Because of the longer On-Time of the LEDs and the >not existing cooling< (or at last very, very inadequate solution with some PCB-Traces) the LED-Chip will die very soon. This product looks like a Scam-Pruduct, simply a Fake UV-LED-Lamp. For the customer it looks like it would work, but it will not do the job and be trash within a short time. … this is very bad.

Vergleich_Original_und_Fake_PCB_inside

Some images in detail from the inside:

 

Compare the USB-cables:

The original cables have a more edgy shape of the connector-housing.

The cables of the fake lamp are very rounded.

Vergleich_Original_und_Fake_USB-Cable_of_the_OriginalVergleich_Original_und_Fake_USB-Cable_of_the_Fake


The result

I talk to the eBay-seller and the problems what I have with the product.

The product looks like the original UVLED-Lamp and they use the same values, but it was clear that it could not do the same job in 30 seconds or 45 seconds if the power of the UV-LED-Chips is much lower.

I started a case on eBay with the reason: The product does not appear to be genuine.”

It takes me one week and 4 detailed answers with pictures to get my money back from this (scam) seller.

Further development

Right now I see that the sellers are selling the same product still on their eBay-Website, but now … for a higher price.

A higher price dispels buyers’ concerns that it could be a scam. High-priced goods are always better than cheap products. 😉  (No, not in this case … they have simply increased the price.)

Look at their new offer:

 

General call: Report to the dealer or eBay that you have received a product that “Doesn’t seem to be genuine.”
Report the design-related problems with the product.
If there were enough complaints, the traders might consider whether they would rather give truthful information and not try to defraud people.

 


This is my message history from eBay:

  • 10. Apr.
    You have sent a message
    Message:
    This device is unusable for me, it is made for scamming people and not to work. It was trash as you have produced it and since I get it, it has not developing to something better. It is still unusable trash. Please talk with your supplier (if you are not involved in this scam). Please send me a full refund.
  • 10. Apr.
    The seller has sent you a message
    Message:
    Dear customer, we understand your situation. We are sorry for this situation. However, this product can still be used. We will refund 5 EUR as compensation. Could you please accept this? We look forward to your reply soon. Yours sincerely.
  • 09. Apr.
    You have sent a message
    Message:
    There are several problems with this device in this condition.
    1. The timer have the wrong time, because of the lower power the device need more time to harden the UV-Gel. It needs 2.4 times longer for the same work, but only if the LED have the same ability.
    2. Because of the overheating of the single LED-Chip, the Output-Power-Effiziency of the LEDs are lower. Because this we have the problem of increasing duration of time. Because of the longer On-Time of the LEDs and the >not existing cooling< (or at last very, very inadequate solution with some PCB-Traces) the LED-Chip will die very soon. This product looks like a Scam-Pruduct, simply a Fake UV-LED-Lamp. For the customer it looks like it would work, but it will not do the job and be trash within a short time. … very bad.
  • 09. Apr.
    The seller has sent you a message
    Message:
    Dear customer, we apologize for this situation. We will definitely improve our quality. We will refund 4EUR as compensation. Could you please accept it? We look forward to your reply soon. Your.
  • 08. Apr.
    You have sent a message
    Message:
    The lamp does not consume the specified amount of energy and does not have the advertised performance. Due to the fact that no aluminium was used for cooling, the chips are getting much hotter. The FR4 glass fiber substrate is a very poor heat conductor, so the durability of the lamp is not guaranteed. What you are selling is simply a cheap copy of the “SUNmini UV Nail Lamp” from SODIAL. Just try it out yourself and measure the energy consumption of the device. The UV LEDs also look very different. I don’t know what you’re selling, but it’s obviously a typical “China scam”.
  • 08. Apr.
    The seller has sent you a message
    Message:
    Dear customer, thank you for your email. We have not seen the situation you are reflecting on. Would you circle it? Thanks for your help. Looking forward to hearing from you soon. Your.
  • 07. Apr.
    You have started a return
    Order number xxxxxxxxx
    Reason for return: Doesn’t seem genuine
    Remarks:
    This 6W LED Nail Lamp has only a power consumption of 2,5W and there is no adequate cooling available, because the PCB is made from FR4 and not made from Aluminium ! This will greatly reduce the shelf life. The original SUNmini – UV LED Nail Lamp is equiped with a Aluminium-PCB and have a power consumption of 6 Watt.

Fake China LED-Baustrahler von eBay

Auf eBay gibt es günstige Akku betriebene LED-Baustrahler von chinesischen Händlern zu kaufen, für knapp 19€ bekommt man scheinbar einen 20W Baustrahler.

Die reale Leistung beträgt aber leider nur 4,8 Watt !

Links ist das Werbebild vom eBay-Händler, rechts ein Foto von der Verpackung:

Werbebild_Baustrahler

Produktbild bei eBay

LED-Strahler_Verpackung

Foto von der Verpackung

Mit im Set ist ein 8,4V Ladegerät für die Steckdose (110V / 230V) und ein 8,4V Ladegerät für den Zigarettenanzünder.

Die Bewertungen bei eBay waren durchweg positiv, aber die Leute schauen wohl nur ob er angekommen ist, ob er funktioniert und geben dann eine positive Bewertung ab.

Der Aufbau :
– Als Spannungsversorgung wurden zwei LiIon-Zellen (Typ 18650, 3,7V) in Reihe geschaltet. Maximale Endspannung beträgt somit 8,4V.
– Das Lade-Netzteil liefert 8,4V und ist strombegrenzt, somit kann der Akku direkt geladen werden, aber wenn man das Netzteil über die Hohlbuchse nur mit dem Akku verbindet, dann speist der Akku die Primärseite des Netzteils und die Status-LED des Netzteils leuchtet.
– Die Strombegrenzung der LED erfolgt über einen 3 Ohm (5 Watt) Widerstand.
– Die 40 LED-Chips des LED-Moduls sind so verschaltet dass zwei LEDs in Reihe und 20 parallel liegen.

LED-Strahler_Vorwiderstand_Akku

Geöffnetes Gehäuse mit Akku, 3Ω Widerstand, Schalter und Ladebuchse.

LED_Modul

LED-Modul auf dem Alugehäuse befestigt

Von der Funktion her ist eigentlich alles in Ordnung, der Akku kann nicht unterladen werden, weil die LEDs bei einer Spannung von 2x 2,4V = 4,8V nur noch leicht glimmen würden und kein nennenswerter Strom über sie fließt. Jede Zelle würden also noch etwa 2,4V Restspannung behalten wenn man die Lampe zu lange an lassen würde. (einen Balancer gibt es jedoch nicht)

Mit den 8,4V (4,2V pro Zelle) bin ich nicht zufrieden (beschleunigte Zersetzung der Elektroden des LiIon-Akkus), aber so machen es halt alle.

Kritik :
– Schon wenn man ein mal kurz durchrechnet welche Leistung solch ein LED-Modul wahrscheinlich hat, dann kommt man auf keine 20 Watt. (Bei einer Annahme von 3V Spannungsabfall an einer LED, damit 6V bei zwei in Reihe geschalteten LEDs und 3 Ohm als Vorwiderstand.) Der maximale Strom der über die LEDs fließen kann liegt bei (8,4V-(2x 3V))/ 3 Ohm = 0,8A. Somit ergibt sich eine maximale Leistung über die LED von 6V*0,8A = 4,8W.

Anhand der Chip-Größe kann man auch die maximale Leistung des LED-Moduls recht genau bestimmen.

Die normalen Osram LEDs haben eine Leistungsfähigkeit von 1Watt pro 1mm² Chipfläche. Um die LED nicht im Maximum zu betreiben nimmt man in der Regel nur 73% dieses Wertes damit die LED eine gewisse Haltbarkeit aufweisen kann.

In dem vorliegenden Fall hat das LED-Modul 40 LED-Chips mit den Abmessungen: 0,5mm x 0,25mm. Damit ergibt sich eine Gesamtfläche von 40*0,25mm*0,5mm = 5mm² , die maximale Leistungsfähigkeit des LED-Moduls liegt somit bei 5 Watt.

LED_Chips-size

Die Leistung ist durch die sehr einfache Strombegrenzung mit einem Widerstand auch nicht konstant, sondern ist abhängig von der Akkuspannung und daher sinkt die Leistung mit der Zeit.

Die Akkuspannung eines LiIon-Akkus liegt zwischen 3,7V bis 4,2V und somit liegt der minimale Stromwert bei ((3,7V*2)-6V)/3 Ohm = 0,466A , was dann einer Leistung an der LED von etwa 2,66W entspricht.  Bei niedrigeren Akkuspannungen erhöht sich der Akku-Innenwiderstand recht stark, was zu einem schnellen Leistungseinbruch führt.

Die Wärmeleitpaste unter dem LED-Modul ist ein Erbsen-großer Fleck, da muss man unbedingt nachbessern.

Positiv :
Das Alu-Guss-Gehäuse und auch die Scheibe machen einen ordentlichen Eindruck.
Die Dichtungen sind auch ganz okay.

 

Leistungs-Messung

Spannung: Über den Spannungsabfall am 3Ω Widerstand lässt sich der LED-Strom sehr einfach berechnen.

Den Akku habe ich mit dem Ladegerät auf maximal 8,36V aufladen können. Bei dem Test sind dann 2,5 Volt am Widerstand abgefallen und 8,36V-2,5V=5,86V (2,93V pro LED) an dem LED-Modul.

Strom: (Formel: I = U_Widerstand/R = (2,5V/3Ω) = 0,833A)

Die Leistung an der LED lässt sich mit Hilfe der LED-Spannung und des Stroms berechnen (P=U_LED * I). Sie beträgt maximal: (2,5V/3Ω)*(8,36V-2,5V)=4,88W

Achtung :
Wenn jemand anderes bei eBay solch einen Akku-LED-Baustrahler (die gibt es in Leistungsstufen von 10W, 20W, 30W bis 100W) gekauft hat, dann sollte die Rückseite ein mal geöffnet werden um zu sehen was da für ein Widerstand verbaut ist, wie hoch die Akkuspannung ist und welche Spannung an dem LED-Modul im Betrieb abfällt. (dort ist kein Siegel vorhanden welches man zerstören könnte und man arbeitet nur mit einer Schutzkleinspannung)

Da bei meinem Scheinwerfer auf dem Typenschild 20W angegeben waren und er nur maximal 4,8W liefert, kann ich aber auch von einem Fake-Produkt sprechen. Da hat nicht nur zufällig jemand den falschen Punkt auf dem Typenschild gesetzt, das LED-Modul ist ja auch nur für 5W ausgelegt. Man soll eindeutig verarscht werden.

LED-Strahler_Daten-Schild

Aufruf: Meldet dem Händler oder eBay dass ihr ein Produkt bekommen habt welches “Nicht wie beschrieben/abgebildet” ist. Wenn es genügend Beschwerden gab, dann werden die Händler sich vielleicht überlegen ob sie doch lieber wahrheitsgemäße Angaben machen.

Ich habe nichts gegen eine günstige Bauweise, so lange sie funktioniert.
Ich habe aber etwas dagegen verarscht zu werden.

Bad quality 100W LED-Modules from china

I have make some tests with LED-Cluster or LED-Modules which I get from china. They have a inner structure of 10 times 10 LED-Chips, 10 lines and 10 rows. The price was pretty cheap, 4.32 Euro for one of them and the quality of the cold-white LEDs was very good.

But … the quality of the warm-white LED-Module was disgusting. Some of the Chips lit up very bright and some other were off. Because of the uneven spreading of the current, every chip have an other energy dissipation. Some of the Chips get 3 or 5times so much current as they can handle if you run the LED-Modul with the desired amount of current of 3.0 ampere.

Because of this the one LED who have the most energy flow-rate is growing old much faster then the other and exactly this LED cause the loss of one LED- line. If this one LED-Line does not work any more, all other Lines get more current and in this lines are bad selected Chips too, which will be destroyed very fast again of this problem.

Here is my first Test with two 100W LED-Modules with chips which are not selected: 100W LED-Mdule Test

I use this LED-Modules only with max. 30 Watt !

How ever, there are 100W Modules which are very good selected too and you can not see at the price, is it a good LED or a bad. There is no sign which is called: “selected LED chips”


I have bought some other 10W LED-Modules () and they are mounted with selected chips, but I do not want to show you what is nice and working. Here you should see that the possibility that you get not selected LED-Modules is very high.

My second Test with 10W LED-Modules: 10W LED-Module Test

Look at the first LED which is lit up in this Video and the voltage along this Line of 3 LEDs. At a voltage of 2.7V over 3 LEDs the LED give light. Normally this should not be possibly, you must apply minimal 3*2.5V=7.5V so that 3 LEDs in one line can glow. Normal white LEDs give light at a current of some micro-ampere, but the voltage drop always exist! There must be a current flow which past the chip, so that there is no voltage drop.

The manufacturers saves one cost and time extensive step, but so they creates garbage what will destroy itself some day.

Here is a nice article with a good quality video of a 100W LED Test: http://hackaday.com/2015/09/14/why-100-watt-ebay-leds-are-not-your-friends/