3Watt LED bulbs

[Felix Bosch]

So I tried to do the prudent thing some time back to replace my 20 outside garden light bulbs from 60watt Incadecent to 3W LED golfballs… packaging and specs declare 95% Energy saving and only 3watt used …. What a load of bull…. I now converted to solar and the use graph is very visible showing that 20 LEDS use nearly 1kW ! Thus on average 50watt each! So being able to, I build a small circuit and tested the current which is 280 to 300mA (tested a few bulbs) thus P = VxIxpf gives 230 x 0.28 x 0.8  = more or less 50watt or more… so how can it at all be claimed that they save any energy? They are turned on 8 hours per night so that is a huge lie and waste of money ito energy saving? I know they may last longer, run cooler and all that, but bottom line is they save NO energy and drain my inverter and money? Any one else found the same ?

[Modina]

May I suggest a simple test.  Try and place your hand on one of those 60W bulbs and see how long you can keep your hand on them.  Then repeat the test with your 3W LED.   Doesn't matter what you do, at the end of the day, just about all electric power is converter into heat.  Sound and light generation is a very tiny amount.  Even mechanical power from an electric motor ultimately is turned into heat, with the exception of adding kinetic or potential energy in applications such as water pumping and the like.

I think your assumption of a PF = 0.8  is way, way to high.

BTW, these cheap LEDs are all overdriven.  The manufacturers purposefully do so, so that these bulbs very seldom see more than 18 or 24 months of life.  Otherwise, who would buy LEDs in future?

Open the LEDs and modify them to run at half power and they will run for many years.  You can check out the youtube videos from Big Clive.  He has made a number of videos going into the details.  See my other posts about this matter.  You could also connect a 0.22 or 0.47uF high voltage cap in series, and that would also dim these lights and reduce the power further.

Edited April 6, 2023 by Modina

[Felix Bosch]

1 hour ago, Modina said:

May I suggest a simple test.  Try and place your hand on one of those 60W bulbs and see how long you can keep your hand on them.  Then repeat the test with your 3W LED.   Doesn't matter what you do, at the end of the day, just about all electric power is converter into heat.  Sound and light generation is a very tiny amount.  Even mechanical power from an electric motor ultimately is turned into heat, with the exception of adding kinetic or potential energy in applications such as water pumping and the like.

I think your assumption of a PF = 0.8  is way, way to high.

BTW, these cheap LEDs are all overdriven.  The manufacturers purposefully do so, so that these bulbs very seldom see more than 18 or 24 months of life.  Otherwise, who would buy LEDs in future?

Open the LEDs and modify them to run at half power and they will run for many years.  You can check out the youtube videos from Big Clive.  He has made a number of videos going into the details.  See my other posts about this matter.  You could also connect a 0.22 or 0.47uF high voltage cap in series, and that would also dim these lights and reduce the power further.

I do know normal incadecent will waste lots of energy is heat, was thinking of 15w units that are mostly resistive so at least not the 40+ watts wasted by the LED in driver. The power factor at 0.5 is even giving 30/40Watts and my measurements on 18 lamps shows 900+ Watts so it is not far out. You do not state that you agree / not agree that they use 40/50 watt per unit in energy where they are maketed at 3W and 95 % energy saving which I call is bull from suppliers and just bad advertising in general. Modifying new units is just not viable to take all appart and get them nicely sealed again including additional soldering onto micro coponent boards…i have more than 80 lamps all over thus will need to find a new alternative that gives good enough light and not consume more than 5w real power!

[JustinSchoeman]

I only have 2x 3W LED bulbs on a day night sensor, and the power draw is too small to pick up any change in inverter power when they turn on.

I would look for something else on that garden circuit causing the power use.

Perhaps just unscrew one bulb at a time, and try to see how much difference there is on your measured power?

[Felix Bosch]

It is a single circuit with the 18 lamps, nothing else. I have tested the complete circuit and also 5 single 3w globes in a simple circuit on the bench too pulling 270/300mA thus the watt calculation for a single unit. Will do some more tests for different manufacturers and also check how much the day/night switch add as it will probably also take some. My other single ligts and even strings of 5/8 also do not even blib above normal inverter house appliance “noise”

[system32]

2 hours ago, Felix Bosch said:

So I tried to do the prudent thing some time back to replace my 20 outside garden light bulbs from 60watt Incadecent to 3W LED golfballs… packaging and specs declare 95% Energy saving and only 3watt used …. What a load of bull…. I now converted to solar and the use graph is very visible showing that 20 LEDS use nearly 1kW ! Thus on average 50watt each! So being able to, I build a small circuit and tested the current which is 280 to 300mA (tested a few bulbs) thus P = VxIxpf gives 230 x 0.28 x 0.8  = more or less 50watt or more… so how can it at all be claimed that they save any energy? They are turned on 8 hours per night so that is a huge lie and waste of money ito energy saving? I know they may last longer, run cooler and all that, but bottom line is they save NO energy and drain my inverter and money? Any one else found the same ?

I'm not so clued up as you in terms of P = VxIxpf and power factors.

I just used my trusty consumer grade kill-a-watt meter.

With a 40W incandescent, the kill-a-watt shows ~42W with a PF of ~99 on the display.
With a 5W (GU10 400 Lumens Cool White) LED it shows ~5.2W with a PF of ~65 on the display.
The LED is much brighter than the 40W incandescent.
Am I missing something?

Edited April 6, 2023 by system32

[Modina]

It is not possible for a 3W LED to consume 40 or 50W.  These bulbs are made 100% of plastic, except for the PCB that is a single layer on an aluminum substrate to act as a heatsink for the LED chips.  If the bulbs would really consume 40W the whole thing would melt.

Somewhere you are making a measuring error.

I don't think for garden applications one needs the full brightness of a 3W.  Dimmed lights are likely to give a better ambienance. Especially if you use so many bulbs.  I would suggest that you connect a single capacitor in series with ALL the LEDs in parallel.  Because you use a lot of bulbs, I would try to use a motor starter capacitor.  It might not work, but I think your chances on 3W LEDs is 80% that it will work.  It depends on the LEDs you use.  It is a very quick and simple thing to test, and you might just be pleasantly surprised.  You have nothing to loose.   Just make sure that the capacitor is rated for 250VAC or at least 600VDC.  Once you see that it works, you might want to try using bigger or smaller capacitors to get the brightness just right for your personal preferences.  Even using a 0.47uF capacitor will cause enough current to power up all your 18 LEDs at a very low level.

I would not want to randomly have to replace LEDs when you use that many.  Another advantage of using a capacitor is that the wiring could literally be short circuited without any ill effects.  Outside wiring has a much higher chance of getting damaged.

[Felix Bosch]

I agree as the 50watt need to go into something and the most likely place is heat and they are not really getting that hot. I will try and do some more tests in due time, removing all bulbs too to see current draw without any in circuit too. I am sure there is a logical explanation as to why this circuit is  using so much. Also re test a few different makes on the single circuit diagram and see what is typical too

[Bobster.]

I'm interested to see the conclusions reached.

I haven't measured BUT my inverter has a habit of turning off at night and drawing from the grid when load gets too low. In an attempt to get the load up and avoid this switching off which was result in a massive... oooh... about 0,7 kWh of grid usage I started burning my exterior lights. Seven of them. There is one CFL, and a mix of LEDs of different voltages, the lowest being 3 W, and the highest being two small flood lights at about 12W each. There are four day/night sensors involved, This has made no discernible difference, so I am puzzled to hear that 3W globes are actually consuming 50W. I'd notice that sort of load increase.

[Scorp007]

22 hours ago, Felix Bosch said:

I agree as the 50watt need to go into something and the most likely place is heat and they are not really getting that hot. I will try and do some more tests in due time, removing all bulbs too to see current draw without any in circuit too. I am sure there is a logical explanation as to why this circuit is  using so much. Also re test a few different makes on the single circuit diagram and see what is typical too

Your concern is an easy one to solve. Herewith the results of a quick test with gadgets on the table.

Test of  7W and 3W LED bulbs. Even with the inverter AC/DC losses the 7W one only used 15.5W.

We ignore the current as measurements as such low currents are not accurate. Thus ignore the PF.

 

Edited April 7, 2023 by Scorp007