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How do I power an LED light strip? Answered

I just purchased an LED light strip from Amazon:

Triangle Bulbs 3528-IP65-White-60L Pure White LED Strip Light, Waterproof LED Flexible Light Strip 12V with 300 SMD LED

12 VDC Super bright Waterproof Cool White 3528 SMD LED strip
    Length:16.4 ft./5 Meter 300 LED lights per reel. Allowable cut every 3 LED lights
    Easy and flexible installation. Ideal for home and business lighting decoration.
    Comes with 3M adhesive sticky backing
    High brightness, wide angle LED chip. Low power consumption - Only 4.8W/m LIfe: 50,000 hours

I already have a 12V DC 2A battery pack. (it holds 8 AA Batteries).

What else do I need to complete the circuit?  I am thinking I need some sort of on/off switch, but have no idea what I need to buy. 




Best Answer 3 years ago

You are doing well.

Based on your batteries find any switch that specifies it can handle 4 or more amps DC, don't be concerned about switch voltage. Radio Shack carries switches.

To verify the select switch, tell us the length of your strip ?

thanks iceng! The total length of approx. 16ft is too long. I will be cutting it down to about 2 ft for the project display I am creating. Doing the math, because I don't yet have the strips, it will run about 35-40 LED's. I do not know how to figure out amps, mAh, or other electric lingo. Mpilchfamily mentioned not needing a switch and I am thinking of using that advice. Do you know if with following that advice I will need to solder anything? I would like to keep this simple because of my low tech skills.

Sure a switch is only a convenience, but you will need to take out a battery or interrupt the current to turn it off.

Your strip needs 4.8 watts per meter close to 2 feet.

Watts is the product of volts times amps. We know 4.8W and 12V.

Amps = 4.8/12 =o.4A or 400 milliamperes . So your 2' strip will use less then four tenths of an ampere.

Now Alkaline AA batteries are rated at 2.12 Amp hours of energy.

So your display should last 2.12 / 0.4 = 5.3h over five hours.....

Thank you :)

Be sure when you connect to the strip to observe polarity !

Battery + to strip + always the RED wire and

Black wire - to -.......


3 years ago

thank you to both iceng and mpilchfamily. Both your answers were equally helpful and gave me the confidence I need to complete my project. Mahalo nui loa! Hawaiian for thank you very much.

final comment. I purchased a switch from radio shack and will complete my project with the led strip, switch, 12v DC AA 8 battery pack.

How many of these 16 ft light strips can I connect together on one 12v power supply?

Shouldn't NEED to buy anything. Connect it to the battery and it's on, remove it and it's off. If you want to add a switch then do so. Nothing more too it really.

thanks mpilchfamily! I like knowing that I don't need the switch and may just do that. I was worried that there was something I was missing. This is my first time connecting LEDs. This is a one time temporary project that will be lit for 1hour. I have 12v DC plugs too, but like the portability off the battery pack.