Need help with LED lighting

Mar 2, 2009 02:03 pm
Need help with LED lighting

I have a smackerel of experience with electronics. None of it is "hands on" experience with LED's.

The following is a link to a PDF file with the specs. for a particular LED.

Is it possible to "wire" 3 or maybe 4 of these in series and then several of those series strings in parallel (maybe as many as 33) to work from a 12 vdc nominal battery bank recharged by photovoltaics?
The plan is to use as an outdoor night light off of the battery, so the higher "working" voltages from the PV array should not come into effect.
Thanks for any help.

26 Posts
Mar 3, 2009 03:56 am
Re: Need help with LED lighting

 Harbor freight has a 33 LED 12 volt drop light .There is one in my kitchen. Comes with a car type 12 volt male adapter. It was fairly cheap I, believe and sometimes they will put items on special sale.

A couple of the LEDS blink at times, until warmed up or three of them may go out but it still works fine for a somewhat bright nightlight.about the brightest light in LEDS  i found for the money,think it was around $20.00

 It would save you having to make one. Unless that is what you want to do.Harbor also has other LED lights but most of the smaller ones all stopped working within weeks (China)sorry. Although think it is just the on switchs not working

Have not taken them apart yet to checkout.The droplight seems to be the best out of all.

Mar 3, 2009 06:25 am
Re: Need help with LED lighting

Thank you Mr.Clay

What we are wanting to do is, convert certain 400 watt metal halide pole top parking lot area lights by gutting the; ballast, capacitor, and mogul base lamp socket from the housing but keeping the reflector and clear glass lens then rebuilding it into a stand alone pole top PV/battery powered, LED counter part.

If its possible to "wire" 3 of the aforementioned LED's in series and then as many as 33, or maybe more, of those series strings in parallel, that would be 99, or more, of those LED lights.

The aim is to create an affordable retro-kit.
Those 400 watt replacement ballast kits with a new bulb can cost as much as $250.00 not including the labor to change it out. So you can figure what it would cost somebody to change them out say, 4 or more times.
Of course I don't how much longer a PV/LED change over would last. Need to build one and find out.
26 Posts
Mar 3, 2009 04:22 pm
Re: Need help with LED lighting


Here are some links to a few websites I found very helpful when I was tinkering with LED's

Hope they help.

Dave C.
33 Posts
Mar 3, 2009 05:35 pm
Re: Need help with LED lighting

Ya that's exactly how you do it. If you were to set up a 12 volt led light on a 48 volt battery you could wire 4 of those bulbs in series to give 12 volts to each light, but all 4 lights would have to be on at once and all have to be working.
That's the only drawback to what you are doing if one of the leds burns out the whole string of series wound lights would go out.

But yes you have the right idea and know what to do. You can also limit the brightness of the led's by limiting their current with resistors. The led's would last about 10 years between changeovers but would last longer if they aren't subjected to high heats and would last longer if they were reisted down to limit brightness just a tad but then you could run into resistor burning out every couple years.

But the led you chose you would probably want to use 4 per series and work on the minimum voltage rating of it unless you use small wire and lose too much voltage in the run up the pole. But if your doing a small charging panel and small battery set up to run it then wouldn't be a problem. Ideal setup would probably be 8 of those in series on a 24 volt system.

One last thing. If you look at the radiation pattern on those. You are going to probabably be more interested in diffusing the light pattern than focusing it. Unless you radially mount those on something so that they look like a light bulb. If you mount them straight square or circle panel (floodlight style) they won't need any focusing at all.
« Last Edit: Mar 3, 2009 05:45 pm by Jonathan Winters »

Disclaimer and Disclosure

The Alternative Energy Store, Inc reserves the right, within its sole discretion, to refuse or delete any posting or portion thereof, or terminate or block the access to this forum.

The opinions and statements posted on this forum are the opinions and statements of the person posting same, and do not constitute the opinion or act of the Alternative Energy Store, Inc (AltE). The Alternative Energy Store, Inc does not endorse or subscribe to any particular posting. No posting shall be construed as the act or opinion of the Alternative Energy Store, Inc.

Click here for BBB Business Review

McAfee SECURE sites help keep you safe from identity theft, credit card fraud, spyware, spam, viruses and online scams
Desktop Website | Mobile Website


Click on an icon to share! If you don't see the method you want, hover over the orange "+".


What can we do to help you?

Please enter a summary
Sorry, the copyright must be in the template.
Please notify this forum's administrator that this site is using an ILLEGAL copy of SMF!
Copyright removed!!