87Views11Replies

Author Options:

leds connected in parallel to a 12 volt battery? How do I do it? Answered

I have 12 led light fixtures - each one has 24 (5mm)  leds in the head.  O/P:DC 10.5 v, 0.5 a written on the wall plug transformer.  I want to cut off the transformer and use them on a 12 volt battery.  Is this possible?  Do I need the resistor in this line?  Can I hook all 12 to a Die Hard?  Please reply PDQ. 

Discussions

0
None
Josehf Murchison

3 years ago

Yea jus add a 1K resistor to the Led, if there are LEDs in parallel do the same for each LED. If they have LEDS in series you will need 3 LEDs or a 500 ohm resistor in series if you have two resistors in series.

0
None
joan1951Josehf Murchison

Answer 3 years ago

Thanks for responding Josehf. We are hoping you can help further. We purchased an LED lamp that plugs into 110 through a transformer at the plug. It says the LEDs are 10.5 v on the transformer. We want to cut the transformer off and use the lamp on 12 volt DC. We actually have 10 of these lamps that we would like to hook up on a 12 volt battery. We are doing an outdoor jewelry show and there is no AC. They need to run 8-10 hours. Is this possible?

0
None
Josehf Murchisonjoan1951

Answer 3 years ago

Sorry for taking so long to respond. You might be able to just hook it up and go. Electronics is ballpark math the components are made depending on the part up to 20% tolerance. Your wall adaptor may be rated 10.5 volts, it could be putting out 13 volts. This is why ballpark math that looks like it is a series parallel light assembly with several branches of 1 resistor and 3 LEDs. For a battery and you want it to work for 10 hours you want a 15 amp hour battery.

0
None
joan1951

3 years ago

I appreciate that info so much. Thank you, Steve. The show is on Sept 12, and I will let you know how it goes!

Kind Regards, Joan

0
None
steveastroukjoan1951

Answer 3 years ago

Don't forget to vote for the Best answer. ;-)

But try one lamp on a 12V battery all night, check it works OK before you commit.

0
None
joan1951

3 years ago

Thank you Steve for the green light on a straight hook up to a 12v battery. One more question - if you don't mind - as my original question stated, I have 12 of these LED light fixtures, each one having 24 (5mm) LED lights. Considering the amount of time (8-10 hours) that I need to run them, what type of battery do you recommend to keep me up and running. Also, should I use more than one battery. Say, 6 LEDs to a battery etc.?

Thanks again Steve -

Kind Regards, Joan

0
None
steveastroukjoan1951

Answer 3 years ago

That means that 12 will take 6 Amps, so for 8- 10 hours life from a deep cycle battery, they'd pull 60Ah, leaving something in the battery, because I hate running them flat, flat, and its not good for deep-cycle, I'd want 80-100Ah of battery capacity to run them all at once, or 2 x 40Ah.

0
None
joan1951

3 years ago

We are hoping to use a deep cycle battery - the type that you would use for a trolling motor. Here are images of the circuit board and the transformer that we removed. Thanks for any help you can give!

DSC_0746.JPGDSC_0739.JPGDSC_0740.JPGDSC_0745.JPG
0
None
steveastroukjoan1951

Answer 3 years ago

Joan, on the basis of that picture, you're good to go straight on 12V.

0
None
joan1951

3 years ago

Thanks for responding Josehf. We are hoping you can help further. We purchased an LED lamp that plugs into 110 through a transformer at the plug. It says the LEDs are 10.5 v on the transformer. We want to cut the transformer off and use the lamp on 12 volt DC. We actually have 10 of these lamps that we would like to hook up on a 12 volt battery. We are doing an outdoor jewelry show and there is no AC. They need to run 8-10 hours. Is this possible?

0
None
steveastroukjoan1951

Answer 3 years ago

THEORETICALLY, these lights should run on DC, what worries me is this very specific "10.5 volts", which suggests to me that if you DID run them on 12, not nice things might happen.

Can you open the lights up, and take photos of the circuit boards to show us ?

Also, a battery pack should run these nicely. What battery are you proposing ? You need at LEAST 5ah