# Source for small 12V 1-2A solar panel charger / controller?

#### spinnaker

Joined Oct 29, 2009
7,835
Thanks but I don't need motion. Perhaps I should mention something about the application.

I belong to a home owners association for a group of townhouses. We have an entry sign that we want to light but there is no power anywhere near the sign and it is close to $2K-$4k to have a line installed depending on how we want to do it.

To solve this problem we purchased a solar powered flag light. I think it is an array of 8 x 16 LEDs. It seemed to work pretty well until the controller went belly up.

I figured I could improve on it my making it micro controller controlled. There are lots of features that I could add.

#### BMorse

Joined Sep 26, 2009
2,675
I figured I could improve on it my making it micro controller controlled. There are lots of features that I could add.

Is there anyway you can post pictures of the device with solar panel (possible a model number and manufacturer).... and possibly a shot of the charge controller circuit board itself? And The Battery it uses? This will give me a better understanding on what you are working with.....

And yes, adding a uc to it would definitely be cool, and it would leave you to add some other options.... possibly a Pic16F628A would do, run it on its internal osc, and use a couple of the ADC pins to attach a CDS to detect the ambient light levels, and use another ADC to detect voltage levels of the battery (Although I would still use an op-amp for this so you can have an external adjustment to it without having to change the code if you ever swapped out the battery for one with different ratings....)

I am actually working on something similar (that is why I had that solar powered motion light tore apart, I was scavenging the solar panel, and white LED's). I have a sign in front of my house for my computer business, and I was going to light it up with some LED lights and use the Pic to do the same thing..... and since I live out in the country where there is hardly any traffic at night, I was going to use some photocells to detect oncoming headlights and then turn on the LED's (this way I save battery power when there is no traffic!)

#### SgtWookie

Joined Jul 17, 2007
22,210
The battery they're using is a 12v 4AH SLA type. I suggest that it would be really hard on it to charge it faster than a 5-hour rate, or about 800mA.

The solar cell can output about 2A through a 9.9Ω load during midday sun.
The dead short current was nearly the same as through a 9.9Ω load resistor. V/R calculated from resistance x current through the resistor.
Rich (BB code):
        9.9Ω
Time   Amps  V/R
10:30am 2.00 19.8v
11:00am 1.98 19.6v
1:15pm 1.79 17.721v
2:15pm 1.6  15.68v
2:50pm 1.06 10.494v
3:35pm 0.54  5.346v
Note that the electronics must fit in a small sealed enclosure, and dissipate as little heat as possible.
[eta]
Here is a datasheet for a similar type: http://www.totalcomputing.net/pdf/enersys/enersys_np412.pdf
Note the maximum recommended charge current is 1A.
Note the cycle depth vs number of cycles:
100% depth of discharge 250 cycles
50% depth of discharge 550 cycles
30% depth of discharge 1200 cycles

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#### HarveyH42

Joined Jul 22, 2007
426
Thanks. I think another poster (I think Bernard) suggested this one too. I am considering it. May be an easier way to go.

But what I am unsure of if it can turn on and off the light. There don't seem to be an specs on it but I guess I could always email AllElectronics.

Or I guess I could always add this feature. I was thinking about adding a Microcontroller anyway so that I can have settable delays and other features. Because most of these controllers just turn on the light when the ambient light has dropped to a point that the panel can no longer detect it even though there may still be plenty of light.

With my microcontroller, I could always turn the lights off after they have been on X number of hours.
Nope, doesn't turn on/off light/load. It protects the battery from over charging, and cuts off the load before the battery is drain too far. I got one from Futurlec years ago that had light controls and timers (still using it), a little more expensive, but not bad.
http://www.futurlec.com/Solar_Charge_Controller.shtml
Mine is about 3 down, the $25.90 5 amp model, I think. EPRC5/24. Pretty good timing function, and shuts off to protect the battery. #### SgtWookie Joined Jul 17, 2007 22,210 Nope, doesn't turn on/off light/load. It protects the battery from over charging, and cuts off the load before the battery is drain too far. I got one from Futurlec years ago that had light controls and timers (still using it), a little more expensive, but not bad. http://www.futurlec.com/Solar_Charge_Controller.shtml Mine is about 3 down, the$25.90 5 amp model, I think. EPRC5/24. Pretty good timing function, and shuts off to protect the battery.
We've already looked at that same model. It needs ventilation; he doesn't have it.
5A is way too much current for his battery.

#### spinnaker

Joined Oct 29, 2009
7,835
Attached are some pics.

The whole works was purchased here.

Remember the board is now dead.

Not sure what all is on there with the coating all over the board. I was wondering what the tiny little chip is on the back side.

The whole works fits inside the light. The new project does not have to fit inside the light. In fact I think it would rather not. It is really tight and I will bet not sealed very well. Plus it is a real pain to change batteries.

There are some nearby shrubs maybe 10 feet away. Or I could just place the enclosure next to the panel. I am going to recommend moving the panel anyway since it is in a very poor position.

I figure I could hide the enclosure in there and run a wire, if you folks thing that is acceptable. I guess I would need some kind of conduit to keep water from leaching into the wire.

But that all comes later, I need to first get the controller built.

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#### spinnaker

Joined Oct 29, 2009
7,835
Some more pics

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#### spinnaker

Joined Oct 29, 2009
7,835

#### SgtWookie

Joined Jul 17, 2007
22,210
Oh, boy. I'm looking at IMG_0862.jpg; the top of the board.

Can you read the part number off that 8-pin DIP IC by R13?

How about some of the other part numbers, like for Q4, Q6 - basically anything that has 3 legs.

The item in the lower right corner has my eye - that's why I said "Oh boy" to start off with. I have an idea that you may have a boost-type supply for the LED array, and you won't be able to just slap in another charge controller and have it work.

It would be helpful to see the back of the LED circuit board.

#### spinnaker

Joined Oct 29, 2009
7,835
I can't see anything on the components. Is there a trick for removing the coating w/o destroying the numbers?

I will see if I can snap a pic of the LED array later today. Off to "real" work now.

#### HarveyH42

Joined Jul 22, 2007
426
We've already looked at that same model. It needs ventilation; he doesn't have it.
5A is way too much current for his battery.
It works fine with under 5 amps, mine only has a 14 watt panel and 7aH battery. It just runs a few LED lights in the house, and a couple of IR spotlights in the backyard for the security camera. Doesn't last all night, but good enough. Need a better location for the panel (damn oak trees).

All he really needs to do is figure out what the lamp requires. Doubt the 5 amp controller would need much air flow, since its not being used anywhere near it's max rating.

The clear/white component at the top center of the first photo, is it a relay or fuse? Both tend to fail...

#### spinnaker

Joined Oct 29, 2009
7,835
The clear/white component at the top center of the first photo, is it a relay or fuse? Both tend to fail...
A fuse and it is blown but I don't think that is the only problem.

#### spinnaker

Joined Oct 29, 2009
7,835
Oh, boy. I'm looking at IMG_0862.jpg; the top of the board.

Can you read the part number off that 8-pin DIP IC by R13?

How about some of the other part numbers, like for Q4, Q6 - basically anything that has 3 legs.

The item in the lower right corner has my eye - that's why I said "Oh boy" to start off with. I have an idea that you may have a boost-type supply for the LED array, and you won't be able to just slap in another charge controller and have it work.

It would be helpful to see the back of the LED circuit board.

Looks like I am unable to get the light apart. Either the screws are totally rusted or those are some kind of pins and the whole thing is pressed together. I would be afraid to drill anything out right now.

Anyway to check it out without tearing it apart?

I did get one part #

Q1 F9540N R608P
Q4 looks like IRF3205 that is about all I can read there.
Q2,Q3,Q6 (and maybe Q5) S9013

Can't really read the rest. Too much coating

#### HarveyH42

Joined Jul 22, 2007
426
I would have changed the fuse first, you'd be surprised how often it's the simplest thing. Will give a word of advice though, those blade type fuses are tough to solder to a PCB. Maybe it just takes a hotter iron, than what I've got. Would suggest a fuse holder instead.

#### spinnaker

Joined Oct 29, 2009
7,835
I would have changed the fuse first, you'd be surprised how often it's the simplest thing. Will give a word of advice though, those blade type fuses are tough to solder to a PCB. Maybe it just takes a hotter iron, than what I've got. Would suggest a fuse holder instead.
I jumped in a fuse after checking for obvious shorts. It blew again. Board appears to be discolored around R6 and R8.

I might try again but need to pick up another 1/2 amp fuse.

#### SgtWookie

Joined Jul 17, 2007
22,210
Looks like I am unable to get the light apart. Either the screws are totally rusted or those are some kind of pins and the whole thing is pressed together. I would be afraid to drill anything out right now.
I see. Corrosion is highly likely.

Anyway to check it out without tearing it apart?
Depends - do you have a variable voltage supply that you could connect up to it? I'm wondering if it operates straight from 12v-14v, or if it requires a boost-type supply.
Q1 F9540N R608P
IRF9540 - P-ch Power MOSFET(Vdss=-100V, Rds(on)=0.117ohm, Id=-23A)

Q4 looks like IRF3205 that is about all I can read there.
IRF3205 - N-Ch Power MOSFET (Vdss=55,Rds(on)=8m,Id=110A)

Q2,Q3,Q6 (and maybe Q5) S9013
A Fairchild SS9013 would substitute; it's an NPN transistor; 40V, 1W, 500mA.

Can't really read the rest. Too much coating
It's tough to get off without destroying printing underneath. If it's laser-etched into the parts, sometimes you can use lacquer thinner - but if you get it on the board, it might eat the lettering off.

#### spinnaker

Joined Oct 29, 2009
7,835
I see. Corrosion is highly likely.

Depends - do you have a variable voltage supply that you could connect up to it?
.
Not yet. That is my first project.

I'm wondering if it operates straight from 12v-14v, or if it requires a boost-type supply.
Works fine when connecting it to a battery. Nice and bright!

#### popawheelie

Joined Dec 28, 2009
2
I don't mean to hijack this thread.
I've been looking for solar products and am having a hard time finding what I want.
Is there a supplier who can sell me the components I need for small 12V DC landscape lighting system?
thanks!

#### spinnaker

Joined Oct 29, 2009
7,835
I don't mean to hijack this thread.
I've been looking for solar products and am having a hard time finding what I want.
Is there a supplier who can sell me the components I need for small 12V DC landscape lighting system?
thanks!

We bought the original light from siliconsolar.com but I was not real happy wit them. That is why I am going to attempt to make my own. Funny I was just about to create a post on this project.

#### popawheelie

Joined Dec 28, 2009
2
Hi Spinnaker, I'm new to this so I could be wrong. It seems to me that there should be suppliers out there that can sell me a system that supports what i want in lighting. I'm just lighting the front landscaping.
It should be just plug in and go. Why do they make it so difficult?
Am I missing something?