Wiring 50 10W+ RGB LED pond lights

**Logan005** · 05-01-2016, 03:42 PM

is this a location with out grid power? 5 X 75ah @ 12 volt batteries wired in series? flooded Lead acid batteries or sealed? Really 50? 10 watt light? is 500 watts. your gonna need a lot bigger battery even for just a few hour run time.

**lukecrawley** · 05-01-2016, 04:39 PM

No grid power. Batteries will be in parallel, system is only 12VDC. Panels in parallel, and lights in parallel. Sealed AGM batteries.

I guess I used the calculator wrong? What should I be looking at for batteries?

**Logan005** · 05-01-2016, 06:14 PM

12 volts is not good for your demands. Your system would need to be 48 volts, Minimum of 6 volt L16 style cells X 8 of them wired in series. you would also need an MPPT charge controller and at least 1500 watt's of solar panels. it is not good to wire batteries in parallel, sealed batteries can not be serviced and last 2 years or so in a cyclical environment. Your load is too large for a 12 volt or even a 24 volt system. Reduce your requirements or be prepared to spend several thousand on batteries ever 2 years or so.

**lukecrawley** · 05-01-2016, 06:53 PM

It's for a temporary art installation, and from what I've read it's extremely common to wire batteries in parallel for solar applications where only 12V is needed, but with long run times. Am I missing something? I'm using 12V LED lights, so I don't need a 48V supply, I just need a 12V supply. I don't think I'd want to put 48V in the water anyway.

**Logan005** · 05-01-2016, 07:27 PM

to keep from wiring batteries in parallel you wire in series and use a step down converter for your 12 volt loads, much more efficient than a 12 volt system. 48 volts would not be in the water, only the battery. Temporary is how long? using a 12 volt parallel wired system, you will be lucky to get 6 months.

**lukecrawley** · 05-01-2016, 07:39 PM

Ah! I wasn't thinking that way. The installation would only technically be for 1 month, but I also don't just want to waste the batteries. I'll look into those 6V cells, thanks!

**Sunking** · 05-01-2016, 11:49 PM

Originally posted by lukecrawley

I need 4hrs per day of run time in a location that gets 4 solar hours per day. I've used a solar calculator to determine I need 5 75Ah batteries and 11 100W panels.

Wrong wrong and foolish. You are pissing away money right and left, and will destroy the batteries. You need to get out of your 12 volt box you are stuck in.

First paralleling batteries is STUPID and IGNORANT. If you parallel 5 batteries, you will replace them every year. If you need 12 volts 375 Amp Hours, buy 365 Amp Hour batteries, They will NOT BE 12 VOLT batteries, They will be 6-volt batteries, two of them wired in series. Something like a pair Trojan L16RE-B a 6-volt 370 AH battery.

Next colossal mistake you are making is using 12 volt battery panels with a cheap PWM controller. You are pissing away a lot of money. First that will turn you 1100 watt panels into 725 watts. Next way too much hardware and gigantic wire. Smart money is to buy yourself 4-250 watts Grid tied panel. GT panels cost half what battery panels cost. At 1000 watts into a 12 volt battery requires a good 80 amp MPPT controller like a Midnight Solar Classic 150. Wire all four panels in series and call it done.

**lukecrawley** · 05-02-2016, 07:57 AM

Wow, thank you, Sunking, your reply was both helpful AND tactful! If you had taken the time to actually read the above posts, this is for a temporary 1-month max art installation, so I don't need a long term solution and how I spend my budget is up to me. Also, you might then have noticed that I have already taken Logan005's advice regarding using 6V batteries in series with an MPPT controller. In addition, this project is off grid, about which you could have inquired instead of assuming GT panels were even an option. Great post, keep it up!

**SunEagle** · 05-02-2016, 09:10 AM

Originally posted by lukecrawley

Wow, thank you, Sunking, your reply was both helpful AND tactful! If you had taken the time to actually read the above posts, this is for a temporary 1-month max art installation, so I don't need a long term solution and how I spend my budget is up to me. Also, you might then have noticed that I have already taken Logan005's advice regarding using 6V batteries in series with an MPPT controller. In addition, this project is off grid, about which you could have inquired instead of assuming GT panels were even an option. Great post, keep it up!

Maybe something that Sunking didn't totally explain was that "battery panels" (200w and less) tend to cost more per watt then "grid tie" panels (> 200W). You can still use grid tie panels for off grid and you will get more output from them with an MPPT type charge controller.

If money isn't a problem and your system is 200 watt or less then going with "battery panels" and a PWM CC will work but can still cost more than using the higher wattage "grid tie" panels.

**Logan005** · 05-02-2016, 09:16 AM

grid tied panels can be used in place of the more expensive 12 volt panels. does not mean they have to be grid tied. A 100 watt 12 volt panel cost about $200, you can get a 250 watt Grid tied panel for the same $200, If you continue with a 12 volt system, you may get one of the four hours of run time you desire. If you insist on 12 volts, I recommend you consider the 2volt version of the L16's, you will need 6 of them in series and will give you close to 1100 AH, and that is close to what you will need. I still recommend at least 1500 watts of panels to charge it with, and an MPPT controller.

**lukecrawley** · 05-02-2016, 10:51 AM

Originally posted by SunEagle

Maybe something that Sunking didn't totally explain was that "battery panels" (200w and less) tend to cost more per watt then "grid tie" panels (> 200W). You can still use grid tie panels for off grid and you will get more output from them with an MPPT type charge controller.

If money isn't a problem and your system is 200 watt or less then going with "battery panels" and a PWM CC will work but can still cost more than using the higher wattage "grid tie" panels.

Originally posted by Logan005

grid tied panels can be used in place of the more expensive 12 volt panels. does not mean they have to be grid tied. A 100 watt 12 volt panel cost about $200, you can get a 250 watt Grid tied panel for the same $200, If you continue with a 12 volt system, you may get one of the four hours of run time you desire. If you insist on 12 volts, I recommend you consider the 2volt version of the L16's, you will need 6 of them in series and will give you close to 1100 AH, and that is close to what you will need. I still recommend at least 1500 watts of panels to charge it with, and an MPPT controller.

Thank you! I appreciate the civil and helpful explanations. I'm not married to 12V at all, a transformer hadn't crossed my mind, and I'll look at all the recommended options. Thanks!

**Sunking** · 05-02-2016, 11:35 AM

Battery panels cost 2 to 3 times as much as GT panels. It takes 300 watts of battery panels with a PWM system, to equal 200 watts of a MPPT system. I listened, you did not.

11-100 watts of battery panels in parallel, requires 11 mounts, 11 fuses, and a huge feeder cable to a 60 amp PWM controller. That will cost you some $2800 to $3500 dollars and you still need batteries.

Or if you would listen you could use 750 watts of GT panels, (3-250 watt wired in series) with small wire, no fuses, and a 60 amp MPPT controler will cost you $1000 to $1400. Add another $1000 for good batteries is still less than your way with no batteries.

So who is listening? Do you value your money? What I can tell you is I value your money more than you do, and listen. But it is your money, piss it away.

**lukecrawley** · 05-02-2016, 11:46 AM

Originally posted by Sunking

Battery panels cost 2 to 3 times as much as GT panels. It takes 300 watts of battery panels with a PWM system, to equal 200 watts of a MPPT system. I listened, you did not.

11-100 watts of battery panels in parallel, requires 11 mounts, 11 fuses, and a huge feeder cable to a 60 amp PWM controller. That will cost you some $2800 to $3500 dollars and you still need batteries.

Or if you would listen you could use 750 watts of GT panels, (3-250 watt wired in series) with small wire, no fuses, and a 60 amp MPPT controler will cost you $1000 to $1400. Add another $1000 for good batteries is still less than your way with no batteries.

So who is listening? Do you value your money? What I can tell you is I value your money more than you do, and listen. But it is your money, piss it away.

Gotcha, thanks!

**MetricAmerica** · 05-29-2016, 07:47 PM

Well, Luke, I hope you did your 12 v system, with your 500 watt load, and 2000 wh per day requirements, not sure anything above helped, but at 41 amps needed will require quite large wiring to go around pond, the further you go the bigger the wire needed. Perhaps doing several smaller systems placed around pond will work better. Will the lights be synced? That wire will not need to be so large.

Wiring 50 10W+ RGB LED pond lights

Wiring 50 10W+ RGB LED pond lights

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