How to make a battery powered supply for LED string

[EdL]

Hello,

I've read and watched some of the tutorials, but am still missing a piece on the battery power source

I'd like to take this item and run the lights via battery and not an outlet

SUPERNIGHT (TM) 16.4FT SMD 5050 Waterproof 300LEDs RGB Flexible LED Strip Light Lamp + 44Key IR Remote Controller

The current power block is an LE AC/DC model yczx-1268 that is a DC12V - 3.0A
**broken link removed**


Cheers,

- Ed

 

[audioguru]

You need a 12V voltage regulator with enough current to power as many LEDs as you have. The voltage regulator needs a battery to power it, but a battery voltage drops as it discharges so the battery voltage must be high enough when discharged to still power the voltage regulator.

 

[EdL]

Awesome, I get a 12V regulator with a 3A and I'm good to go. I didn't realize how much battery/energy this would take. I had some party hats that had over 100 LEDs that was powered with just some small batteries, and thought that 6-8 AA would do the trick, but probably not.

 

[audioguru]

If you look at the datasheet of an Energizer AA alkaline cell you will see that its voltage drops pretty fast when its current is only 250mA. It starts at 1.5V then after 2 hours its voltage is less than 1.3V.
Its maximum internal resistance is 300 milli-ohms (plus the resistance of a connector) then at 3A its voltage loss is 3A x 300 milli-ohms= 0.9V so its voltage is less than 1.5V - 0.9V= 0.6V when it is brand new and it would be dead in a few minutes.

 

[AnalogKid]

The current power block is 12 V / 3 A, but that doesn't mean that the LED's need all 36 W.

1. With a 12 V source, what is the current drawn by the LEDs? This will let you make a more appropriate battery selection.
2. How long must the LEDs run on one battery charge?
3. What is your skill set? Do you want to wire a circuit from scratch, buy a regulator module on ebay, or what?

ak

 

[koolguy]

Hello EDl,
i have seen both Power supply and i have also used the same with different manufacture anyway you can also use transformer 0-12V with rectifiers.

 

[audioguru]

It looks like the controller for those multi-color LEDs cannot easily be powered from a battery. You would need to cut it open and find where it produces the 12VDC.