idea on powering up LED using Batterys for an Art Project

[Les Jones]

I think you are being very optimistic expecting to draw 10 to 20 amps from AA cells. This is how I made my ring light for macro photography.
**broken link removed**
Even though the LEDs are mounted on an aluminium ring they still get quite hot after a few minutes and that is only about 12 watts. "Angel eye" LED ring lights sold on ebay for cars may be a solution to your problem. These step up voltage regulators **broken link removed**
sold on ebay by various sellers can easily be modified to be a constant current source but they have a maximum output voltage rating of 35 volts so they only power two of your 10 watt LEDs in series. This is the modification to make them constant current output https://lesjhobbies.weebly.com/led-driver-01.html

Les.

 

[Shay]

I think you are being very optimistic expecting to draw 10 to 20 amps from AA cells. This is how I made my ring light for macro photography.
**broken link removed**
Even though the LEDs are mounted on an aluminium ring they still get quite hot after a few minutes and that is only about 12 watts. "Angel eye" LED ring lights sold on ebay for cars may be a solution to your problem. These step up voltage regulators **broken link removed**
sold on ebay by various sellers can easily be modified to be a constant current source but they have a maximum output voltage rating of 35 volts so they only power two of your 10 watt LEDs in series. This is the modification to make them constant current output https://lesjhobbies.weebly.com/led-driver-01.html

Les.

i don't know by my calculations

with my setup, if i'll have 2 , 9V batterys in series i'll be expecting to go for around 40 minutes before they will die (is that calculation normal you think ? for mycircut )
and if i'll have 6 AA batterys again around the same 30-40 minutes life spend beore they will go dead...

as for the angle eyes ones, yea i added a video of a person doing a camera lens with 3 of this. but i afraid it will only use around half the light intensity as my 20 10w LED lights ...

 

[Les Jones]

The 10 watt 9-12v LEDs consist of three groups of three LEDs connected in series.The three groups are connected in parallel. The voltage rating does not mean you can feed them from any voltage in that range. It means that the voltage across them will be in that range when driven with their rated current of 900 mA Ideally you sould drive them from a constant current source but provided the supply voltage is known and stable you can get away with a series resistor. As you plan to have 20 of these LEDs in parallel this will be a current of 18 amps. Here is a chart I found giving the rating of AA alkaline cells. The maximum current it gives figures for is 2 amps being drawn from a cell. At this discharge rate the best is about 1 AH (Excluding the lithium version which are very expensive.) Even if the would still give this capacity at 18 amps (Which they won't. ) they would last for 3 minutes 20 seconds. To get 12 volts you would need 8 cells in series. If you look at the shape of the discharge curve you will see that the voltage has fallen significantly long before they have given their rated capacity. The next problem you have with 200 watts of LEDs is the heat generated. I have not been able to find figures for the efficiency of LEDs but I would guess at about 25% If that guess is about right then 150 watts of the 200 watts input would be heat that you would have to get rid of. That would require a very large heat sink. You may have to consider a pumped water system to a remote radiator. One possible way round these problems may be to them at reduced power while setting up the picture and trigger them to full power with the remote flash connection on the camera.
Link to AA cell capacity chart. https://www.powerstream.com/AA-tests.htm

Les.

 

[audioguru]

An ordinary 9V alkaline battery can provide only about 400mA for 10 minutes when it has discharged to 7V and the low voltage causes LEDs to be very dim.
Each of your LEDs is 10W so the current for two in series is 10W/9V= 1100mA. A little 9V alkaline battery cannot supply a current that high.
And you want twenty of these LEDS?.

 

[audioguru]

I disagree with the AA battery test. NOBODY uses an AA cell until its voltage has dropped to 0.1V!
They show an Energizer Titanium cell being much more powerful than an Energizer Max cell but on their datasheets all their spec's including weight are exactly the same. I think there is a manufacturer using titanium down the street from the Energizer factory and a few molecules of Titanium drift in from the air.

 

[Shay]

An ordinary 9V alkaline battery can provide only about 400mA for 10 minutes when it has discharged to 7V and the low voltage causes LEDs to be very dim.
Each of your LEDs is 10W so the current for two in series is 10W/9V= 1100mA. A little 9V alkaline battery cannot supply a current that high.
And you want twenty of these LEDS?.

well on the video i linked, he did light it up with 6 AA batterys.... and it'sthe same setup.. i'm even using less voltage Leds...

 

[Tony Stewart]

Then get exactly the same cheap parts and make it exactly the same way as the 1st video and find out for yourself when the CD starts warping and melting.

-typical single LEDs drop from 3.1 to 2.8V from full to no power

 

[audioguru]

The video uses COMPLETELY DIFFERENT LEDS than the ones you have. Maybe their current is MUCH less than yours. He turned down the voltage so they did not get too hot then their light output was also turned down. Maybe his camera is very sensitive and the light LOOKS bright in the video but is not.