How to connect LED strip to batteries

[jesse salinas]

i hope I'm posting this in the right spot. but hello, was wondering if someone could help me. I'm still new to this sort of thing and was trying to do a project with the attached picture. basically, i wanted to connect the D cell battery holder to a push button to power the LED strip lights. from everything i was reading i thought i had it right but it wont work. I'm using D cell because i wanted to power at least like 6 separate strips. at this point I'm stuck, any help would be appreciated

 

[hevans1944]

The 3M strips likely require more than the 3 V available from two D-cells. Try increasing to four cells (6 V) or six cells (9V) or even eight cells (12 V), all connected in series-aiding (so the voltages add up).

What is the part or model number of the 3M strips you are trying to use? Do you have a datasheet for these LEDs? IIRC, current limiting is built-in to the strips by virtue of a chip for every three or four consecutive LEDs on the strip. Whatever that do-dad is, that you have soldered in series with the red (positive) wire from the battery holder, it is not necessary.

 

[jesse salinas]

really? the cells only put out that much? well shit. but looking at the LED package there's really nothing in it that would give you the info your asking for. but from what i see its a 24 watt/reel, 300-3528 LED/reel. i hope that helps. would switching the battery type help perhaps? trying to use 8 cells sounds like abit much and thank you

 

[(*steve*)]

Yeah, they get called 1.5 volt batteries because the nominal voltage is 1.5 volts.

Larger batteries (e.g. D vs AA) have the same nominal voltage, but are capable of higher current, or the same current for longer.

 

[jesse salinas]

ah, but if i have it only a push button sort of thing, then would like double AAs suffice? i get thought that id need like a larger battery holder thought

 

[Bluejets]

trying to use 8 cells sounds like abit much and thank you

Most I've seen can actually be anywhere between 12v or as much as 24v.
Forget the AA. Actually forget the batteries.
Some can take 2 amp for 5 metre string.
Best to show just where you bought them if you cannot provide any specs.

And as Hevans says, forget the do-dad.(resistor I think)

 

[jesse salinas]

Most I've seen can actually be anywhere between 12v or as much as 24v.
Forget the AA. Actually forget the batteries.
Some can take 2 amp for 5 metre string.
Best to show just where you bought them if you cannot provide any specs.

And as Hevans says, forget the do-dad.(resistor I think)

i got them from them from frys, i was actually kind of surprised by how little it had beyond a how to sheet of paper lol. and the resistor was there because from what i was reading it said it needed it something about slowing down the flow of power or something.

what do you mean by 2 amps thought? and really i do appreciate all the help

also idk if this helps but the reason im trying to use batteries of sorts is because its going to go on something that im going to be carrying around.

 

[(*steve*)]

A lot depends on the power required by the LEDs.

The more power they require, the longer you want them to operate, and the brighter you want them to be, the larger the battery needs to be.

If we can find out the power requirement for the LEDs, and how long you want them to operate, and how brightly, we can recommend the capacity (and therefore size) of the required battery.

 

[Nanren888]

Can't quite read the part number on your photo. What's the 3M part number? Look up the voltage you need.
Bigger 1.5 volt cells contain more total energy, so will last longer, once you get enough end-on-end to light the strip.. As bluejets says, it's going to be too much for any small battery. You're going to need a power supply, generally available from the same supplier. Tell them what it's for.

 

[Bluejets]

Ok....so now we are at frys.....I'm assuming that is Fry's Electronics....don't really know as I'm Googling whatever little info you are offering. Just give us a number or link even so we can see what you already know so someone can help you out. Gee it hard sometimes!

 

[jesse salinas]

My bad, really bad at at this but, from what I can see in the strips, I don't see a part number but I see dc12v.

Ohh okay so at this point I just need a bigger power supply gotcha, I'm guessing one that would output more or the same as the strip needs?

I guess it would be as bright as it can be and it doesn't need to be on all the time, if anything it's gonna act more like a flashlight, hence the push button I was trying to use

Looking at the website I'm pretty sure this is it https://www.frys.com/product/8564299#detailed

Really sorry for the lack of info, I Really should have gathered it all before I started asking things

 

[Harald Kapp]

from what i see its a 24 watt/reel

That would be 2 A. The Specs on the site linked in post #10 state

5 meter strip only draws 1.5 amps of current.

the resistor was there because from what i was reading it said it needed it something about slowing down the flow of power or something

Typically LEDs require current limiting and a resistor is the most simple tool for doing this. These LED strips, however, come with built-in current limiting resistors. All they need is a 12 V power supply capable of delivering the above mentioned 1.5 A ... 2 A.
You wil not be happpy with D-cells in the long run. You'll need 8 of them in series to get at 12 V. A D-cell has a capacity of around 13 Ah (13000 mAh) which means that at 2 A the battery stack will be drained within 6.5 hours (13 Ah / 2 A).

The strips you linked to are meant to be operated on a car's 12 V electrical system which is capable of delivering 2 A for an extended period even without the motor running. For home use I recommend you use a suitabel power supply (wall wart) with 12 V output voltage and 2 A or more output current.

 

[jesse salinas]

The strips you linked to are meant to be operated on a car's 12 V electrical system which is capable of delivering 2 A for an extended period even
without the motor running. For home use I recommend you use a suitabel power supply (wall wart) with 12 V output voltage and 2 A or more output current.

Oh I didn' know those were for a car, so at this point I just need a power supply cappleable of running 12v then, and from looking around, seem like a miniature car battery is what need then, like the attached picture.
From what I also get is that it all needs to be like a circle or something like the circuit would be battery to push button to light and then back to the battery, right?

Im stuck having to use a battery for a power supply because this project is going to go on something I'm going to be carrying around, and the push button is because it's mostly gonna act like a flash of light. At most id have it on for like 2 or 3 seconds per button press

 

[Harald Kapp]

the push button is because it's mostly gonna act like a flash of light.

Look at the datasheet of your pushbutton and ensure it is capable of switching 2 A or more.

 

[jesse salinas]

Look at the datasheet of your pushbutton and ensure it is capable of switching 2 A or more.

I shall for sure check when I get home, and I will admit that I did not know that was also going to be factor, thank you

 

[hevans1944]

@jesse salinas: I think you may have finally "got it". Good point that Harald made in his post #14 about the push-button switch. Make sure it can handle at least two amperes of current. As for the battery... if you are gonna be carrying this around, a belt that holds eight D-size cells, either alkaline (one time use) chemistry or rechargeable LiPO, lithium-ion, or even NiCd (nickel cadmium) or lead-acid chemistry would be better than that clunky, heavy, awkward-to-carry, box-like battery whose image you posted. However, that, too, would work just fine, and it is rechargeable.

The important thing is to have enough voltage (12 V DC) and enough current capability (2 A) and enough ampere-hours (8 Ahr or more) energy capacity to last for as long as you want to be outside to use it. You might want to consider making your own "battery belt" using commercial off-the-shelf single-cell holders wired in series with an appropriate connector for the LED strip:

If you are only going to pulse the LED string on for a few seconds, a few times per hour or a few times per minute, you may be able to get by with much smaller cells, say, AA-size or C-size instead of D-size. If it were my project, I would gather up eight fresh 1.5 volt AA alkaline cells and wire them up in series, head-to-toe, with short lengths of stranded 18 to 24 AWG insulated wire. Then make a test run to see how long they will last in the field. Wrap the string of cells with duct tape and secure it to your waist to carry comfortably. Once you find a size that works for you, glue single-cell holders to a web-belt, wire them up, and head on out into the field.

I am curious. What the frak is this? An old-fashioned sandwich-board advertising display? Gotta be more attractive than those stupid inflatable hot-dog displays that waggle around to catch your attention...

 

[jesse salinas]

I am curious. What the frak is this? An old-fashioned sandwich-board advertising display? Gotta be more attractive than those stupid inflatable hot-dog displays that waggle around to catch your attention...

I'm not sure what you mean by this, but yea I'm starting to understand it abit better, thanks. But thinking about how I'm going to maybe use it, think I'm going to go with the big one, just gotta strap it down properly with bands it something.

Now that I get that, comes the fun part of trying to also know how to put multiple strips all to that one battery, since I'm going to cut that roll Into maybe strips of a foot and a half

 

[hevans1944]

... Now that I get that, comes the fun part of trying to also know how to put multiple strips all to that one battery, since I'm going to cut that roll Into maybe strips of a foot and a half

Make sure you cut the strip at the right places. The cutting places should be clearly marked on the strip. Generally, three LEDs (minimum) or an integer (whole number) multiple of the minimum number is required for each strip cut from the reel.

The two outer edges of the strip carry 12 V DC power, one being the positive terminal and the other the negative terminal. You just wire (use stranded, insulated, wire and solder) all the positive terminals together and then wire (use stranded, insulated, wire and solder again) all the negative terminals together. Connect the now-commonly connected positive terminals of all the LED strips to the positive battery terminal. Connect the now-commonly connected negative terminals of all the LED strips to the negative battery terminal. Place the switch in series with one of the battery terminals (either one will be okay) to turn power to the strips on and off. That's all there is to it. Have fun!

 

[jesse salinas]

Awesome so I was looking around curious would this work as a power supply https://www.walmart.com/ip/EverStart-PowerSport-Battery-Group-Size-ES4LBS/16795219

From the specs it' 12v ,4.5Ah. Pretty much what I need right?

 

[(*steve*)]

It looks like it would work. It would give you a runtime of a little more than 2 hours.

If you don't want it to run at full brightness all the time, you can get a PWM controller which will allow you to dial up a brightness.

At less than full brightness you battery will last longer.