120v AC to 12v DC - LED Lights to Battery

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pookerton

Joined Jan 11, 2021
4
I tried searching but was having a hard time finding the proper results.

I've included two pictures and will include the links to each page. What I am trying to accomplish is to connect these 120v AC LED lights to my battery; which I use to run my fish finder.

I've purchased a switch and in-line fuse. The battery has a male spade terminal so I've used piggyback style spade connectors to have my fishing unit connected and the lights at the same time.

However, I just cannot understand what I need to do to get these lights up and running. Would very much appreciate the help if someone could explain. Thank you!

Battery: https://ampedoutdoors.com/products/30ah-lithium-battery-lifepo4-replaces-20ah-same-size-and-weight

Light: https://www.menards.com/main/lighti...46-c-7490.htm?tid=-2165879555910705482&ipos=6
 

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Tonyr1084

Joined Sep 24, 2015
6,866
I am trying to • • • connect these 120v AC LED lights to my battery; which I use to run my fish finder.
You can't. 120VAC has two things your battery doesn't. First, your battery has 12 volts, not 120 volts. Second, it has DC. Your LED (light strip) needs AC.

If I may make a suggestion, since you have a 12V battery go to an automotive parts store and buy some light sockets and some 12 volt LED tail lamps. That will work for what it sounds like you want to do. No need for inverters, which are far more expensive than LED tail lamps and sockets. Plus, you're keeping things safe by NOT having 120VAC on your boat. Otherwise, if you want to modify the control box - it will take considerable work and skill.
 

Thread Starter

pookerton

Joined Jan 11, 2021
4
Appreciate the tips.

I am curious to understand. If you look at the picture of the LED lights there is a box and I wonder if that is adapting the LED lights to be 120v AC. If so, what if I cut the line before that box. Any thoughts would be appreciative. Thanks.
 

Tonyr1084

Joined Sep 24, 2015
6,866
That box converts 120VAC to 12VDC. There are typically four lines with color changing LED strips. One line is a common line and the other three are powered by a varying current going to each color-string. By turning up the Red and Green you get Yellow or a color based on what those two colors combined make. And perhaps those varying colors are controlled by the duration a particular color is lit. Add in the Blue and you can get many different colors. But the box has a lot going on inside. First it converts 120VAC to 12VDC. Likely - and I don't know this for sure - it uses PWM (Pulse Width Modulation) for regulation. Then there's a microchip or some other sort of smart chip that controls the color changing sequence. Finally, there's the intensity control, which "Probably" controls the amount of current going to each color-string.

You can build your own control using three potentiometers (pots for short) to control how much current goes to each string. But now you give up the automatic varying color patterns that are programmed into the box controller. I have something similar in my spa. Slow sweeping through the entire color range to create "Chroma-Therapy" or CT. Soaking in the jetted tub with Pink Floyd playing while lights slowly change color - one can get quite lost in the sensory of light, sound and turbulent waters. It's a nice way to relax after a hard day of work or shoveling snow. But lately we haven't had much snow. But snow is off topic.

I would have to open the box controller to see IF there's a way to feed 12VDC to it. It might be doable. In fact, it probably IS doable. I just wouldn't know how or be able to tell you how to.

Can I ask why you want color changing lights on your fishing boat? I can see a "Party" boat; music and lights. But fishing? Since a fishing trolling motor is pretty quiet I'd imagine playing music while fishing would be counter productive. I've never tried night fishing. Unless you're doing it by the light of the full moon.
 

Thread Starter

pookerton

Joined Jan 11, 2021
4
The light is for my ice fish house to run off my 30ah 12v DC lithium battery that powers my fish finder.

I purchased them not so much for the color changing aspect (they just came that way) but because of the waterproof nature of the roll.

To you point if I cut before the box I'd likely have 12v DC with the R,G,B and 12v.
 

Thread Starter

pookerton

Joined Jan 11, 2021
4
They make the same type of "rope" lights for 12 volt operation. Why not simply get the proper product.
Absolutely. I had this one already. It originally wasn't intended on being used for this purpose.

Was trying to understand if I removed the in-line box which accepts the 120v AC and converts to the LEDs which I assume are 12v if I could make it work.
 

Reloadron

Joined Jan 15, 2015
6,536
Appreciate the tips.

I am curious to understand. If you look at the picture of the LED lights there is a box and I wonder if that is adapting the LED lights to be 120v AC. If so, what if I cut the line before that box. Any thoughts would be appreciative. Thanks.
The problem with cutting the line is the box in addition to making a low DC voltage also controls the color changing of the lights colors. You can likely use an inverter as mentioned but something I am unsure of is how the light supply (little box) which is designed for a 120 VAC 50/60 Hz sine wave input will react to the MSW (Modified Sine Wave) from most inexpensive inverters. Not like you need a lot of power, likely a cheap 200 watt inverter would suffice, I am just not sure about the wave shape. An inexpensive 200 watt inverter runs about $20 to $25 USD a true sine wave output likely a 300 watt will run about $50 USD.

Ron
 

MisterBill2

Joined Jan 23, 2018
11,615
It might even be possible to tap into the connection from tghat little box to the LED strip and discover what voltages are present, and be able to provide them from another source. Of course a detailed examination of the light string may reveal the connection scheme as well. The challenge with assemblies like this is that usually there are LRDs in series and so the voltage required is greater, often some inconvenient level.
 

Reloadron

Joined Jan 15, 2015
6,536
I am not sure that you can actually do that as you need 120 Volts AC to run those lights, and you only have 12 volts. I am not quite sure how you can do it, but I think an invertor might actually do the job. However, you have to find a converter that could convert 12 volts DC into 120 volts AC. I have never done such a thing, actually, so I am not sure about it. Dude, just get a proper led lantern and attach it to the air conditioner, and that will do :DD. I am joking, but I really do not think that you can convert that amount of voltage.
Just as a side note going from 12 VDC to 120 VAC 60 Hz is not a problem at all. Inverters are now common off the shelf items. Heck just here in my house I have several UPS (Uninterruptable Power Supply) battery powered backup units. Some use 12 VDC and some use 24 VDC batteries. On the AC side you can have pure sine or modified sine wave output. A Google of Power Inverter will bring up dozens of hits and depending on power demand they are inexpensive.

Ron
 

MisterBill2

Joined Jan 23, 2018
11,615
Certainly the rope light LEDs do not run on 120 volts AC. And certainly they need a specific voltage at some constant current to illuminate. But so far we don't have a clue as to the purpose. Is the rope light for decoration, illumination, , or safety visibility?That affects how much power you need and the voltage you use.
 

ThePanMan

Joined Mar 13, 2020
357
Here's what I'm imagining: A rope light who's color is not important to the TS. The rope light is controlled by a box that converts 120VAC into 12VDC and in accordance with whatever lighting scheme is set, it modulates the R, G & B LED's to achieve whatever color the system is capable of reproducing. If I wanted something similar and I had this rope in hand I'd just chop out the box and power each set of LED's by a switch. Then I could turn Red on if I want light but not scare away the fish (assumed). Or turn the Green on for whatever reason, or turn on the Blue. Turn both the Red and Green and get some sort of Yellow light, or whatever light they would produce. Green and Blue for yet another color, Blue and Red for a Purple color, or all three sets of light on in order to get White light.

If brightness is a concern and there's no desire to modulate the brightness, a single resistor on each line could set the light level. If you want it to be adjustable then you'll probably need to build your own PWM power supply to change the brightness.
 

Reloadron

Joined Jan 15, 2015
6,536
The thread starter has not been back since January 11th of this year so I figure they found a solution. No way to know exactly what LED type they had. Some color changing rope lights are just RGB lamps and use PWM for color change and some are digital using an address to change color. Regardless after 7 months into it my best guess is they solved their problem. While I have never messed around with the addressable strings I have written a little code using a uC to PWM tri color (RGB) led strings. Here is an example of a 12 VDC RGB string I used to experiment with.

RGB Strip.png

They were a common anode string.

LED4.png


Schematic wise they look like this.

5050 LED String.png

I drove the MOSFET gates DIO1, DIO2 and DIO3 (RGB) with a uC. You can change colors, fade in and out, pretty much whatever trips your trigger. The addressable strings are an animal of a different color and while I have seen circuits for them I never messed around with them. Anyway less knowing what the thread starter actually had it's sort of hard to guess a solution and after 6 months I doubt they need one. :)

Ron
 

MisterBill2

Joined Jan 23, 2018
11,615
I am not sure that the TS ever said the lights were 12 volts in the string, but rather that they wanted to run them from the 12 volt battery for the trolling motor. So the actual voltage is probably unknown. I have some failed LED tube lights with strings of 24 LEDs in parallel so each string gets the same 72??? volts. Unfortunately they do not last in even a sheltered outside installation, but inside the same type lasted 3 years so far.
 

Reloadron

Joined Jan 15, 2015
6,536
We likely never will know exactly what the thread starter had. I used a 12 VDC string merely as an example. The string is exactly as I drew it. A good friend of mine bought an entire kit to decorate his motorcycle. Joe Florida LED lights. We spent several hours a night putting them on his bike. We got it done and the bike resembled a LED Christmas tree. He paid a heck of a lot more than I see in the Amazon link. Anyway, we get it done and he looks at me and says "now we need to order a set for your bike". They even had a cute little wireless remote for different effects and colors. I was no I don't think so. Not quite my taste. I see my bike like a truck or rifle, an extension of my personal taste and I don't want a Christmas tree bike. Anyway just out of curiosity I bought a cheap 12 volt DC string and played around with them until the novelty wore off and my curiosity settled. Retired with no plans to work again projects like that keep my mind occupied. :)

Anyway I guess we just assume the thread starter solved his problem.

Ron
 

ThePanMan

Joined Mar 13, 2020
357
The TS has a string of LED lights that are powered from a 120VAC source. That source goes to a converter module that drops the voltage down to something the LED's run on. They're definitely LED's if they change color. If they're common then they are operating on 12 volts - give or take a little; and they're probably controlled for brightness via PWM or Constant Current. It's probably safe to assume the string can be operated by simply connecting a 12 volt source across what is probably the +12 and the R, G & B lines. Powering all three lines (in this case, grounding them) will produce white light.

Just what the purpose of these lights on a boat powered from a trolling motor's battery - I can't begin to guess. But if the TS wants to convert 12 volts into 120 volts via an inverter then plug in the lights to 120 VAC - eh. Whatever you wish to do. But I think it's safe to assume these are 12 VDC.
 

MisterBill2

Joined Jan 23, 2018
11,615
I cedrtainly would NOT presume the lights are 12 volts DC,because that is not the cheapest way to produce strings of light. A larger number of LEDs in series across the DC supply allows thinner wire, and that is a real savings. Count the number of LEDs in the tring , and try to gain acces to the leads and measure the voltage. If the TS is not able to do that, then a 120 volt inverter is the best choice.
 
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