Floodlight flickering

[sensij]

At what distance and beam spread?
Led's tend to be directional

Although these questions matter for the apparent brightness, they don't when considering the premise that AC LED's are somehow more efficient than DC LED's. A lumen is, by definition, omnidirectional... it is simply a measure of light emitted . It is only when you start looking at lux or candlepower that how the light is distributed becomes a factor. There is a nice table in wikipedia showing the typical relationship between lumens and watts for different kinds of light sources.

For two sources, if one consumes twice the electrical power, but emits double the lumens, they have the same efficiency. Playing with different designs to get more of the emitted light where you want it and less wasted is one way to get more utility out of a lower wattage bulb, but that is a different tangent.

[sensij]

But that does raise the question - is part of those 2200 lumens being wasted in some direction that you wouldn't want in a flood? To be fair to both, what is the testing criteria that each follow before they rate them for sale? Is it the same?

Lumens tells you only how much is emitted, it doesn't tell you where it goes. Lux or Candela is a better measure of luminous power over a specific area. The GE data sheet has charts showing what those curves look like as you move away from the source.

[SunEagle]

Lumens tells you only how much is emitted, it doesn't tell you where it goes. Lux or Candela is a better measure of luminous power over a specific area. The GE data sheet has charts showing what those curves look like as you move away from the source.

I agree. You need the charts or curves of a specific fixture to know if you are getting the right amount of light on your target.

A lighting design usuaully starts with a required # of FC (foot-candles) on the target surface. After a fixture and "light source" has been selected you include the "LD & DD" (Light and Dirt depreciation) factors in the formula to get the calculated output after the light has been install over a period of time. You don't want the light output to drop off below the required FC amount before the lamp life is half over.

The amount of light (lumens) a source puts out does not mean it will all get to the target surface based on the type of lens or reflector being used. So getting the right type of light source for a task can get a little complicated.

[joelonly]

Thst narrows things down a bit.
What is the model of the chsrge controller and panel where is the system and how many hours a day is the light on.

5.5hrs average

[Naptown]

5.5hrs average

Incomplete answer

[Leon_chow]

Anyone can help me? i have 50W off grid solar system, 12V/30W LED floodlight directly connected to the solar controller. 50Ah deep cycle battery.
New battery only lasted for 6 months, the LED floodlight flickering. What is the possible problem
Thanks

Joelonly

There are some questions:
1. Do this flood light has a regulator in it?
2. Do the controller combined a constant current power pack?
You know, the system can only has one constant current for flood light. If the controller has a constant current pack, u can take the regulator away from flood light, and make sure the input voltage is suitable for the controller.