Solar powered lights in the garden at St James Catholic Church, Coorparoo.

TerryK

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Sorry it's taken me so long to reply. (Is it possible to get an email reminder when someone responds to a post?)

What I've been thinking about is running everything off a 12v battery. There are cheap solar controllers that are designed to charge 12V batteries, with "street light" control, like ...

... series of distribution points at 1.2 and 3.6 volts, as the lights seem to come mainly in single or triple 1.2v series, and multiples of 1.5v for the common non-rechargeable battery-powered lights which are cheap and readily available. The existing lights I would rewire to attach to those distributions. ...
As i13 mentioned, one can 'watch' a thread but as I understand it, a thread one initiates or contributes to is automatically 'watched'. What also needs done is in the user profile is a checkbox to receive emails and notices, which obviously would need checked. Another method is to periodically check the website and look at the 'alert' icon (shape of a bell) located on the right side of the website 'ribbon'; also to the right of the website username.

Using 12 volt is all right but I would avoid any fractional voltage division as mentioned in a previous post doing so creates a loss of efficiency. Loss of efficiency really needs seriously avoided in a low power application which I think what you are attempting is. One typically would also avoid passive components as much as possible; resistors for example.
I looked at the charger/controller, noticed that it did not specify compatible battery types and solar arrays; so a bit lacking in specifications in my opinion. Jaycar I see does list units which are not too much more expensive that would I think be a better fit.

I think at this point it would help if you could indicate a quantity of lamps and one or two types you are considering. A solar panel too if you have thought about it any. Also considering I'm in the 'other' hemisphere, typical swing of daylight hours between summer and winter.

Somewhat beside the point but I have about 20 solar lights that I am getting ready to convert for Christmas. Plan is to convert them to 12 Volt WS2811s.
 

Mark_M

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Some of the reverse polarity ones run at 31V and work on the Hanson's DMX2-18/DC2811-2 controllers
This is going to be more fun added into the mix.

But is 31v the highest score? Nope! :oops:
I had an Arlec branded set of rope light. Solar panel took 2 3.6v Lithium Ion batteries.
The thing outputted 70v to the string of lights. Absolutely mad.

This is the rope light seen flashing on this spiral tree:
View: https://youtu.be/Dos39scqpbw?t=16

I sent 5v directly into the solar panels circuitry. The two 3.6v batteries in series is more than 5v, but under powering it worked.

I really wanted to cut out the flashing circuitry, but getting a 70v power source was too much hassle.
In previous years I used DC buck converters to take 12v to a higher voltage, but I learnt the lesson that this is very inefficient and wastes soo much heat.
 

Notenoughlights

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This is going to be more fun added into the mix.

But is 31v the highest score? Nope! :oops:
I had an Arlec branded set of rope light. Solar panel took 2 3.6v Lithium Ion batteries.
The thing outputted 70v to the string of lights. Absolutely mad.

This is the rope light seen flashing on this spiral tree:
View: https://youtu.be/Dos39scqpbw?t=16

I sent 5v directly into the solar panels circuitry. The two 3.6v batteries in series is more than 5v, but under powering it worked.

I really wanted to cut out the flashing circuitry, but getting a 70v power source was too much hassle.
In previous years I used DC buck converters to take 12v to a higher voltage, but I learnt the lesson that this is very inefficient and wastes soo much heat.
Did you test open circuit voltage or with a load. Open circuit the solar lights measured about 65VAC. Closed circuit, about 26vAC.
 

Mark_M

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Did you test open circuit voltage or with a load. Open circuit the solar lights measured about 65VAC. Closed circuit, about 26vAC.

[Full time elf, 100th post!]
I can't remember sorry.
I'm guessing I would of measured with the lights still connected because I didn't want to de-solder them from the board until I knew.

Given that our posts have exploded since pbw replied;

I suggest we cut back on posting too much in this thread until we know more from pbw.
We don't want to throw every possible variable out there and cause confusion :).
 

pbw

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I went off solar powered lights when they came to this reverse polarity nonsense. I buy battery powered lights because they're all steady on.
For this very reason in using a separate power supply.

Great tip too; "seed lights" are very good for outdoors. Unlike the standard LEDs, these seed lights are dipped in resin and don't corrode out.

--------

Oh sorry.
I thought you were meaning to effectively wire the standard solar strings in series to each other, like a 12v strip with 3 LEDs in series to across 12v.
Taking a small section of 12v lights and placing them into garden lights or something is a great idea.

I'm thinking that if @pbw has standard fairly lights, with each LED in parallel, max of 3v could be sent through the string (like mine run at 3.3v).
Thanks to everyone who replied. I'm overwhelmed by the responses, and I'll have to work my way through them.

I have one lot of "wire lights", which I think might be what you call "seed lights". Here's the arbour.
IMG_20200423_180123495.jpg
The crown of stars was made from a string of 100 "wire lights" like so.
IMG_20200402_182538905.jpg

and I want that especially, and the arch lights, to stay on all night.

It's a popular little shrine, and people from the church and the priests have added various solar-powered lights to the garden. The mauve illumination of the statue of the Blessed Virgin is from a light which cycles through a series of colours (something you would be familiar with here) and is powered by quite a large panel. I haven't had a close look at it yet, so I don't know what the voltage is. That one will have to have its controller in order to do its cycling.

i recall reading somewhere (maybe even in the a.c.l. manual) that the critical variable with leds is current, which must remain within certain limits. Can anyone confirm that?

There's been a lot of feedback here that I have to work my way through. Thanks again.
 

i13

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That's correct about the current needing to be bellow a certain threshold. It is often possible to calculate the correct current for a string of LED lights by looking at its wiring up close. Increasing the voltage increases the current that flows. Considering that these are solar lights, it is possible that they're presently being run at an even lower current to increase the time before the batteries run out of charge. This is done at the expense of brightness.

Those are seed lights in the picture.
 

pbw

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Using 12 volt is all right but I would avoid any fractional voltage division as mentioned in a previous post doing so creates a loss of efficiency. Loss of efficiency really needs seriously avoided in a low power application which I think what you are attempting is. One typically would also avoid passive components as much as possible; resistors for example.
I looked at the charger/controller, noticed that it did not specify compatible battery types and solar arrays; so a bit lacking in specifications in my opinion. Jaycar I see does list units which are not too much more expensive that would I think be a better fit.

I think at this point it would help if you could indicate a quantity of lamps and one or two types you are considering. A solar panel too if you have thought about it any. Also considering I'm in the 'other' hemisphere, typical swing of daylight hours between summer and winter.

Somewhat beside the point but I have about 20 solar lights that I am getting ready to convert for Christmas. Plan is to convert them to 12 Volt WS2811s.
I'm looking at a small panel like this one: or maybe the 10 watt equivalent, depending on what sort of load I end up calculating. So far, it's not very great.

As to sun, is you go to this site, and load the json file I have attached (to which I have added a .txt extension for uploading - just remove the .txt), you can play with the sun path.
 

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TerryK

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I'm looking at a small panel like this one: or maybe the 10 watt equivalent, depending on what sort of load I end up calculating. So far, it's not very great.

As to sun, is you go to this site, and load the json file I have attached (to which I have added a .txt extension for uploading - just remove the .txt), you can play with the sun path.
That panel will be too small I suspect. Short circuit, it produces about 300 mA. The website does not really tell me what I am looking for which is good 'sun' hours falling on the panel. Actually, you should be looking at the good 'sun' hours for the shortest day. Knowing that, one can calculate an approximate mAh battery that the panel can recharge. Although, this is really the cart in front of the horse. Determine the load and then design the supply to that.
 

pbw

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That panel will be too small I suspect. Short circuit, it produces about 300 mA. The website does not really tell me what I am looking for which is good 'sun' hours falling on the panel. Actually, you should be looking at the good 'sun' hours for the shortest day. Knowing that, one can calculate an approximate mAh battery that the panel can recharge. Although, this is really the cart in front of the horse. Determine the load and then design the supply to that.
Shortest day, at least according to that site, has10h26m of daylight. 'Good' sun hours would, I suppose, be something like 7. Winter is usually good for sunlight in Brisbane. So that would be around 2100mAh of recharge on a "normal" shortest day with that panel.
That's correct about the current needing to be bellow a certain threshold. It is often possible to calculate the correct current for a string of LED lights by looking at its wiring up close. Increasing the voltage increases the current that flows. Considering that these are solar lights, it is possible that they're presently being run at an even lower current to increase the time before the batteries run out of charge. This is done at the expense of brightness.

Those are seed lights in the picture.
Thanks for the confirmation.
 

TerryK

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Thanks. That gets us a bit closer. Trying for worst case or somewhat near that, we now know that what ever is pulled from the power source over about 14 hours has to be replaced within 7. Something to consider is, view the site and look for a panel location that will optimize those 7 hours. Or could 2 panels in an inverted "V" be used; catch the early day sun on one and late day sun on the other. Put another way, can the 7 hours be increased.
Also, try to determine the approximate number of lights. If I had the correct location, Google Satellite shows a "X" sidewalk pattern. Are you planning on lights on one side or both? Spacing?
The existing lights; crown and arch, typical amperage? 12 Volt?

Food for thought only at this point, to minimize supply discharge, rather than having the lights constant on at a regulated current (when on), can they be multiplexed?
 
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