Author Topic: LED Lighting for 24 VDC Ststems  (Read 2195 times)

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armadillo

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LED Lighting for 24 VDC Ststems
« on: September 09, 2017, 05:07:17 AM »
On my last off grid home I had used some 24 VDC Edison base LED lights on circuits I used when I didn't want to run the inverter, which saved me 30 watts most of the time when needs were minimal. Currently building another off grid home and would like to incorporate the same logic.
The biggest disadvantage I've encountered (and I'm no expert here) is the cost and availability of 24 VDC lighting components. I found many suppliers claimed their bulbs were good for 12-24 VDC, but they were not capable of withstanding typical charging/equalizing voltages encountered in 24 VDC systems. I used some Edison type 24-30 VDC bulbs purchased from Independence Electric and had good life out of them but they are about twenty bucks a pop and really adds up when you need 20 of them to start.

Does anyone here know of a supplier of cost-effective 24 VDC LED lighting components?

tanner0441

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Re: LED Lighting for 24 VDC Ststems
« Reply #1 on: September 09, 2017, 07:01:40 AM »
Hi

Look for Truck and Bus lamps. I needed some temporary lighting for outside  to run from a transformer. I bought several truck spotlight bulbs. 8W a piece.

Brian.

Mary B

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Re: LED Lighting for 24 VDC Ststems
« Reply #2 on: September 09, 2017, 02:40:58 PM »
I built my own and used a buck converter that can handle up to 30 volts.

Led http://www.mpja.com/500-Lumen-7-Watt-Super-Bright-Warm-White-LED/productinfo/32077+OP/

Buck Puck driver http://www.ledsupply.com/led-drivers/buckpuck-dc-led-drivers

Then surplus CPU heatsinks with fans because they do produce a bunch of heat!

dnix71

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Re: LED Lighting for 24 VDC Ststems
« Reply #3 on: September 09, 2017, 03:15:41 PM »
Have you tried 24v landscape lighting? It's 24v ac so the peak to peak is much higher. You might not get full brightness as the device probably have a full wave bridge and if you feed it dc you will only be using 1/2 of the input.

armadillo

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Re: LED Lighting for 24 VDC Ststems
« Reply #4 on: September 09, 2017, 09:13:57 PM »
Thanks for the replies. I'm only an amateur electrician and completely incompetent when it comes to electronics. I'm afraid I'd be in over my head trying to work in AC lights or drivers. Over 99% of truck lights are 12 VDC.

12 VDC Edison LED lites are widely available. Is wiring two 12 volt bulbs in series off 24 volts a good practice?

Don't yachts use 24 VDC lighting? I can't find anything on boat lighting on the net.


armadillo

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Re: LED Lighting for 24 VDC Ststems
« Reply #6 on: September 10, 2017, 08:00:51 PM »
I think superbrightleds is giving us all the rope we need to hang ourselves with. Like ebay, there are lots of LEDs around claiming to be good for 24VDC, but the voltage range is too low and charging batteries will kill them.
Look at the voltage range they give on this one:

https://www.superbrightleds.com/moreinfo/off-grid-led-lighting/a21-led-bulb-80-watt-equivalent-24-vdc-800-lumens/4298/#tab/Specifications

joestue

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Re: LED Lighting for 24 VDC Ststems
« Reply #7 on: September 10, 2017, 08:20:51 PM »
my guess is there is a boost converter in there to bump 18-24 volts up to 33-36v or so needed to supply 10 leds in series.

armadillo

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Re: LED Lighting for 24 VDC Ststems
« Reply #8 on: September 10, 2017, 08:29:46 PM »
Some of the Sundanzer DC freezers are designed to run either 24 VDC or 12 VDC, hook it up the same way either voltage and they work just fine. But the max allowable voltage is rated at 30 VDC or so.

Running 10 bulbs in series seems like it would require 10 times as much voltage ?  I prefer a lighting circuit wired in parallel unless the economics of doing otherwise really makes sense and the system is uncomplicated.

joestue

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Re: LED Lighting for 24 VDC Ststems
« Reply #9 on: September 10, 2017, 10:39:11 PM »
Some of the Sundanzer DC freezers are designed to run either 24 VDC or 12 VDC, hook it up the same way either voltage and they work just fine. But the max allowable voltage is rated at 30 VDC or so.

Running 10 bulbs in series seems like it would require 10 times as much voltage ?  I prefer a lighting circuit wired in parallel unless the economics of doing otherwise really makes sense and the system is uncomplicated.

who said anything about bulbs in series?


if you want to run 24v electronics that can't handle 31 volts for equalizing, you could equalize half your battery bank at a time. that would leave you with 15.6 + 13.6 volts which would be 29.2 volts.

28 volts should be enough for equalizing anyways.
« Last Edit: September 10, 2017, 10:51:17 PM by joestue »

armadillo

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Re: LED Lighting for 24 VDC Ststems
« Reply #10 on: September 11, 2017, 07:43:06 AM »
I'm not a gadget guy. With electronics, equalizing is too many steps to memorize as it is, I don't want to make it any more complicated.   I believe in the K.I.S.S. principle. I was just wondering if there was any simple and cost-effective solution to my 24 VDC lighting needs.

Simen

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Re: LED Lighting for 24 VDC Ststems
« Reply #11 on: September 11, 2017, 11:55:31 AM »
Well;,if you want to sacrifice a little efficiency, a DC-DC converter from 24 to 12V would do it (F.ex. Victron's converters can handle up to 35V.); then you could run all your lights at a steady 12V. Plenty of cheap and good 12V led-bulbs out there...

I run a 12V system in my house, with dc-outlets in every room, and are about to rewire my solar/battery to 24V. But i do not have any need for 24V at the outlets in the house - only for the inverter and reducing cable-loss from panels, so i'll insert a dc-dc converter in line to the outlets...
« Last Edit: September 11, 2017, 12:02:31 PM by Simen »
I will accept the rules that you feel necessary to your freedom. I am free, no matter what rules surround me. If I find them tolerable, I tolerate them; if I find them too obnoxious, I break them. I am free because I know that I alone am morally responsible for everything I do. - (R. A. Heinlein)

Bruce S

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Re: LED Lighting for 24 VDC Ststems
« Reply #12 on: September 11, 2017, 02:20:12 PM »
Your best bet would be to email Superbrightleds directly
They are nice people only 15 miles from my house and almost became my employer.
Their website has changed again, the older one had way too much info for the average user. Looks like they've dumbed it down unfortunately.

Hope that helps
Bruce S
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Mary B

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Re: LED Lighting for 24 VDC Ststems
« Reply #13 on: September 11, 2017, 03:52:38 PM »
LED fixtures have built in voltage and current controllers that are needed for long LED life. Search and find ones that can handle up to 32 volts!

armadillo

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Re: LED Lighting for 24 VDC Ststems
« Reply #14 on: September 12, 2017, 06:49:03 PM »
Well;,if you want to sacrifice a little efficiency, a DC-DC converter from 24 to 12V would do it (F.ex. Victron's converters can handle up to 35V.); then you could run all your lights at a steady 12V. Plenty of cheap and good 12V led-bulbs out there...

I run a 12V system in my house, with dc-outlets in every room, and are about to rewire my solar/battery to 24V. But i do not have any need for 24V at the outlets in the house - only for the inverter and reducing cable-loss from panels, so i'll insert a dc-dc converter in line to the outlets...
Thanks, this is an interesting option. I will have some 12 VDC loads anyway and I was thinking of getting a Samlex DC-DC converter, but the Orion is much more efficient!  95% compared to 85%.The only downside to 12 VDC lighting is the copper wiring needed to keep voltage drop within range. Some of the runs will be over 40 feet. I'm using 10-2 romex.  I'll have to mull this over. In any case I'll get one for other DC loads.

Simen

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Re: LED Lighting for 24 VDC Ststems
« Reply #15 on: September 13, 2017, 12:05:23 AM »
You could keep the 24 V on the longer runs, and putting a smaller dc-dc converter at the load end. I have some routers and switches that i want to run directly from the bank, but they want 12.0 V +/- 5%, so putting a smaller converter (adjusted to 12.5 V) at the end, near the equipment would keep the voltage steady.
It does add to the complexity of the system, though... :)

I will accept the rules that you feel necessary to your freedom. I am free, no matter what rules surround me. If I find them tolerable, I tolerate them; if I find them too obnoxious, I break them. I am free because I know that I alone am morally responsible for everything I do. - (R. A. Heinlein)

armadillo

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Re: LED Lighting for 24 VDC Ststems
« Reply #16 on: September 13, 2017, 10:26:58 AM »
Your best bet would be to email Superbrightleds directly
They are nice people only 15 miles from my house and almost became my employer.
Their website has changed again, the older one had way too much info for the average user. Looks like they've dumbed it down unfortunately.

Hope that helps
Bruce S
Well I just called them. They told me their 24 volt LED's did not have any range, just 24 volts. He told me they weren't made for solar or any battery bank, they were made for grid 120 VAC with a converter for 24 VDC.

DamonHD

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Re: LED Lighting for 24 VDC Ststems
« Reply #17 on: September 13, 2017, 12:03:59 PM »
Sounds like you got the office junior on the phone!

They do "not have any range"?  So is that 24.0V or 24.00000000000000000V?  Not a sensible or useful answer, nor one good for customers or sales.

Rgds

Damon

armadillo

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Re: LED Lighting for 24 VDC Ststems
« Reply #18 on: September 13, 2017, 12:29:17 PM »
Sounds like you got the office junior on the phone!

They do "not have any range"?  So is that 24.0V or 24.00000000000000000V?  Not a sensible or useful answer, nor one good for customers or sales.

Rgds

Damon
Yes, I think I got the office idiot. He could not seem to comprehend that many or most people looking for lighting for 24 volt systems need components that can survive normal system operating voltages and that many of the "24 volt" lights he sells probably have a very short lifespan because of that if the range is truly 24 volts. I even explained that "24 volts" is not a range, but that didn't sink in either.

Bruce S

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Re: LED Lighting for 24 VDC Ststems
« Reply #19 on: September 13, 2017, 01:04:21 PM »
It does sound like you got a new person. I'm not even sure if this guy actually passed the test they give.

Give me a little bit, I'll go visit them and see who's training these bozos and get the info.  8)

Their original biz was replacement bulbs for cars.

Bruce S

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DamonHD

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Re: LED Lighting for 24 VDC Ststems
« Reply #20 on: September 13, 2017, 01:26:28 PM »
Yes Bruce, do them a favour and let the CEO know that the phone training needs improving!

Rgds

Damon

Bruce S

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Re: LED Lighting for 24 VDC Ststems
« Reply #21 on: September 13, 2017, 02:02:40 PM »
DamonHD
Funny you say that. I called he wanted to know if I was still interested it the position. AND yes they are hiring.
I would LOVE to jump, but alas the pay is too far below my minimum  :(. Perhaps in the next 1/2 dozen years when I'm in retirement mode  :o

Now , for the question at hand:
The 24Vdc bulbs can handle anything as low as 20Vdc and as high as 28Vdc. At 21V you'll see crazy high current needs during the on-rush (turn on) IF they even come on. This is a bit complicated as it depends on the number of LEDs in the bulb or strip. The 29V is just as complicated as you're pushing against the forward voltages of the LEDs themselves.

OF course, depending on how far the battery setup is from the lights, the higher voltages might not be a real issue, but the lower one certainly will. Line loss even for 24Vdc systems can be a factor.
Their marine bulbs are built with battery charging regimes in mind.

Armadillo
We might need a little more information on your setup to better help. Distances from batteries to closest light and farthest light. Battery types , wire size (though I think you said Romex )
 
Here's hoping this helps
Bruce S
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armadillo

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Re: LED Lighting for 24 VDC Ststems
« Reply #22 on: September 13, 2017, 07:46:01 PM »


OF course, depending on how far the battery setup is from the lights, the higher voltages might not be a real issue, but the lower one certainly will.
I've been off grid for 8 years and have never been down to 21 volts . 29 volts is not uncommon. I think a system should be designed so that lights will not self-destruct if turned on while equalizing and that could be above 30 volts.

If only one bulb is on, isn't there much less voltage drop than when six lights are running on the same circuit? If so, that's when that one bulb would be subject to the highest voltage.
Quote

Armadillo
We might need a little more information on your setup to better help. Distances from batteries to closest light and farthest light. Battery types , wire size (though I think you said Romex )
 
Here's hoping this helps
Bruce S
Batteries are going to be Trojan L-16REB 6 volts x eight. Distances and wire size are going to be typical, all over the place, but mostly 10 gauge runs, many 40 to 50 feet.

mab

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Re: LED Lighting for 24 VDC Ststems
« Reply #23 on: September 14, 2017, 03:11:06 AM »
I've noticed that a lot of modern 12v leds such as strips are designed to run off a 12v regulated psu and are just a string of 3 leds and a resistor. The older units designed as substitutes for halogen are built with proper switch-mode psu's and are generally God to over 30v

armadillo

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Re: LED Lighting for 24 VDC Ststems
« Reply #24 on: September 14, 2017, 05:08:57 AM »
I've noticed that a lot of modern 12v leds such as strips are designed to run off a 12v regulated psu and are just a string of 3 leds and a resistor.
It makes one wonder why they didn't choose a voltage like 18 VDC or 36 VDC so that people wouldn't make the mistake of using them in place of lights for 12 VDC systems, where they would soon fail. Perhaps they figure they'll make money selling them to the wrong market, then when dissatisfied buyers try to return them they can play the "specifications" excuse.

DamonHD

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Re: LED Lighting for 24 VDC Ststems
« Reply #25 on: September 14, 2017, 05:40:11 AM »
I don't link there's any need to invoke malice here.  The subtleties of the difference between 12V and a nominal 12V system are going to be beyond most people who barely grasp what volts and amps are.

Rgds

Damon

kitestrings

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Re: LED Lighting for 24 VDC Ststems
« Reply #26 on: October 27, 2017, 06:48:32 AM »
Here are a couple more sources that we've used.  I particularly like some of the marinebeam lights that we've used.  They have several that have capacitive touch on/off/dimming with night lights.  Several are 10-30V input.

They seem to also offer better color choice than many suppliers.  If you been to a home with 6,000K LED lights you feel like you'r in a interrogation room.  2,500-2900K for residential lighting is much kinder IMO.


http://store.marinebeam.com/
http://www.led-cfl-lighthouse.com/page/1433707