12V Community Garden Sign - Need help with calculations.

[stevef22]

Hello all, nice to be here on this forum!

I fabricated a large metal sign for our community garden. ( Looks pretty cool if I must say so myself. )

Behind the sign I placed 200 - 5630 LED modules from ebay. Total of 600 LEDS



What I have purchased

200 - 5630 LED Modules ( 3 LEDs each, 600 LEDS total )

1 - Kyocera KD140GX-LFBS 140 Watt 12 Volt Solar Module

1 - Car battery

1 - Solar Charge Controller 12V



I need help with equipment and following questions...

1. What percent of battery will I use up if LED lights turn on for 5 hours? ( I understand you should draw less than 50% of battery for long life )
2. Should I get a deep cycle marine battery?
3. What battery would you recommend for regular use charging/discharging 600 - 5630 LEDs for 5 hours every evening?
4. Comparison running brighter 200-5630 LED modules VS 200- 3528 LED modules? What is power, current draw difference?
5. Do you recommend any other equipment? ie. Solar panel, battery, charge controller.

Please see pictures and links for reference.

Thank you for your help!













Link to solar 12V charge controller I purchased on ebay
http://www.ebay.com/itm/351281210673...%3AMEBIDX%3AIT

Link to LED Modules I purchased on ebay.
http://www.ebay.com/itm/111930123341...%3AMEBIDX%3AIT

[sensij]

Those appear to use something around 1.5 W for each 3 LED module, or 300 W for all 200 of them. You could probably verify that with a current probe during your tests. 300 W * 5 hours = 1500 Wh. Probably looking for a battery with at least 500 Ah at 12 V... 4 of the Trojan L16RE-B's in series parallel might be about right. You would need to generate at least 60 A of charge current to maintain it, probably close to 1000 W of panels with an MPPT controller.

If what I'm looking at is accurate, the 3528's drop to 1.2 W per 3 LED module... reducing the energy need 20%. You may be able to drop to a smaller battery at that point, but it is still pretty serious. Either of these will kill a car battery fast.

Any chance you can get access to grid power near the sign? It would be a heckuva lot less expensive.

[stevef22]

Thanks senij for helping with math. ( Horrible at this stuff) I thought LEDs were energy efficient and use barely any wattage?!@

Dang this can get very expensive very fast : (

No power on building where sign will be hung. Trying to go off grid


Am I missing something here. Take a look at this....

http://www.bestlightingbuy.com/the-comparison-of-3528-and-5050-led-strips.html

This looks to be way less for 300pcs of 3528 LED? Am I right or still dumb?


Thanks for your help.

Comparison of SMD3528 and SMD5050 300-LED Light Strip
	SMD3528 (300 LEDs)	SMD5050 (300 LEDs)
LED Qty	300 pcs	300 pcs
Viewing Angle	120°	120°
Voltage	DC 12 Volt	DC 12 Volt
Current(A)	2Amp	6Amp
Power Consumption	24 Watt	72 Watt

[sensij]

Yeah, what I had been looking at was probably wrong. For the smaller LED, at 50 W for 600 pcs, 5 hours is 250 Wh, 1/6th of what I estimated before. Any decent 12 V, 100 Ah battery would get you going, and you could get the 10 A of charge current from a pair of 12 V panels (like what you already bought) in parallel with a PWM controller, or maybe just your one panel with a 10 A mppt controller would get you close.

[stevef22]

Found specs on ebay ads for both 3528 and 5630 LEDS

5630
0.72W per string = 3 LEDS

3528 per string = 3 LEDS
0.3W

So if I have 600 LEDS...

0.72W = 432Watts
0.3W = 180Watts

Am I correct on this?


LED Quantity: 3 5630SMD leds per string
Color: Warm White
Color Temperature: 3000-3500K
Output power: 0.72W per string
REMARKS: *20pcs means 14.4W, to power up 20pcs you will need a 1.2A DC power supply which is not included in this listing.*
( DO NOT connect led directly to 110v outlet use only 12V AC power supply)
Protection Rate IP65(Waterproof)
Adhesive fixed: double-sided adhesive*Adhesive is for first step fixation, to permanately fix the strings you will need extra fiber glues.*
Interface definition: AWG 20 # wire, gray is positive, white for the negative
Standard cascade: 20PCS
Shell material: PVC plastic material
Sing String Size: 75(L)*12(W)*2.5(H) mm

---------------------

Specifications:
Type:Module 3 LED 3528 SMD
Optional color:Cool White
LED quantity: 3PCS
Beam angle: 120 °
Light Source Life: 50.000H
Working voltage: DC12V
Power: 0.3W
Adhesive fixed: double-sided adhesive
Shell color: white
Size: (about)7.8cm*1.5cm*0.5cm
Standard cascade: 20pcs
Shell material: PVC plastic material
-----------------------------

[sensij]

Each string is 3 LED, so multiply the string wattage by 200 for 600 LED's total (200 modules), based on what you've described. 144 W for the big one, 60 W for the smaller one. The smaller one will be a dramatically different budget, probably your better choice if you can live with the brightness.

[jflorey2]

Thanks senij for helping with math. ( Horrible at this stuff) I thought LEDs were energy efficient and use barely any wattage?

They are very efficient. Use enough of them and they will take a lot of power.

"Efficient" does not mean "takes very little power" - "efficient" means "converts power to useful light/work very effectively." The Tesla Model S is a very efficient car - it still pulls half a megawatt when accelerating hard.

[stevef22]

Ok, I get it now.

144 Watts for 5630LEDS total

60 Watts for 3528LEDS total

I can use 3520 LEDS

What battery would you recommend for 5 hours of run time every evening?

[Sunking]

Figure it out yourself. Here is how. Determine

1 Watt Hours use din a single day. Watt Hours = Watts x Hours. example 200 watts x 5 hours = 1000 wh or 1 Kwh.
2. Multiply by 5. Example 1000 wh x 5 = 5000 watt hours or 5 Kwh
3.. Find battery Amp Hours = Total Watt Hours / Battery Voltage; Example 5000 wh / 12 volts = 416 AH. Call it 400 to 450 AH @ 12 volts.
4. Cry your heart out because a decent 3 to 4 year 12 volt 400 AH battery will cost you $1000. In 3 or 4 years replace it at higher cost.

Want Solar to charge it?

Cough up another $1000 to $1500 depending on your location and shading issues.

[jflorey2]

144 Watts for 5630LEDS total
60 Watts for 3528LEDS total
I can use 3520 LEDS
What battery would you recommend for 5 hours of run time every evening?

You want to discharge to about 20% every night. This allows a few days of autonomy (when it's cloudy) and will make your batteries last longer. So at 100 watts/5 hours that's 500 watt-hours a night. That means 2500 watt-hours or 2.5 kilowatt hours total battery storage. 2500/12= 125 amp hours. I'd use two Trojan T105 type flooded batteries (around 220 amp hours) to make a 12V system. You can get them at Costco for around $100 each; they are often called golf cart (GC2) type.

[Logan005]

use less LED's maybe 20 to 30 watts worth. (still too much) also get yourself a street light charge controller. set you LVD to 11.9 or 12 volts. and allow the controller to do everything, including turn everything off mid morning when battery reaches about 12 volts. Otherwise this set up will cost you 4 to 10 times as much as POCO. Hook those LED's up to DMM to verify the amp draw. I have used similar LED strings and the label is usually off in regards to real world use. also they tend to dim over time. one string put's out half the light a year later. IDK if mine are same brand but look the same.

[Logan005]

Also your battery looks like a crank battery, wrong battery for cyclical use.