Solar charger charge controller

CC38EL · 08-21-2007, 07:41 AM

For all of us who have the 15 watt solar charger, have any of you found a charge controller with that device?

Is a charge controller built in? Is the charged wired directly to the batteries without a charge controller?

If there is one in the system, where would it be for an Ultimate Advantage?

TIA.

CC38EL · 08-21-2007, 07:41 AM

For all of us who have the 15 watt solar charger, have any of you found a charge controller with that device?

Is a charge controller built in? Is the charged wired directly to the batteries without a charge controller?

If there is one in the system, where would it be for an Ultimate Advantage?

TIA.

Rocky Larson · 08-21-2007, 07:58 AM

Here is a link that mentions smaller (15watt) panels don't usually have a controller.

http://www.campingworld.com/tLibrary...t.cfm?ID=39061

I don't know the wattage cutoff for a controller requirement but I am pretty sure you will find yours is well below it. Good Luck

FrontRangeRVer · 08-21-2007, 10:55 AM

I have a solar charger, and my light (on the control panel wall) would blink during bright sunlight, and Winnebago replaced my "controler" under warrantee. I was thinking that it was under the wall near the status light....not sure though. I do know there is a controler though...

FrankO · 08-22-2007, 05:12 AM

Since I just fixed mine I can lend some help. I had an issue that after my first outing where my LED was showing a charge during daylight hours I stored and covered the MH. When I found my batteries going down during a visit to the storage yard, I decided to cut a hole in the cover to expose the Solar Panel. The light would not come on so I thought I had a problem with the Panel/Controller. This week I brought the MH home to prepare for a 2 week jaunt to the Black Hills and decided to look into the Solar problem.
I was told by a member on this forum that there is a board behind the "One Place" so I dropped the panel. What I found was a small board with a connector for the Solar In and Solar Out, 3 diodes/rectifiers and an LED. This is the Controller Board (about 1" square). I have a good friend who is a EE and drew a schematic of the board. Very simple operation. I disconnected the connector from the board and measured across the SI (Solar In). You should see ~20V (Solar Panel). Then measure across SO (Solar Out) and you should see ~13.5V (battery). Now the hard part, we rehooked up the connector and saw the power increase at SO to ~16V. This meant that the board was working and my issue was the LED. Went to Radio Shack, bought 2 packs of LEDs at $1.25 per pack. Took off the bad LED and soldered on the new one and wala, good to go. Reassembled everything and we are ready to go.
Hope this helps -- Frank

FrontRangeRVer · 08-22-2007, 05:19 AM

Good post Frank!

I think my problem was the led also, and Winnie just replaced the whole 1" board.....problem solved also!

CC38EL · 08-22-2007, 05:23 AM

Thanks to all for the replies. Based on what I've learned and Franks recent experience, there is some controlling going on.

Now the next question is: What is the rating of this controller board? How do we find out how much it can handle?

I'm thinking of upgrading the stock panel to a 50W or higher. It would be nice if the controlling board could handle the increase.

FrankO · 08-22-2007, 07:28 AM

ua40j:
I spoke to my buddy about upgrading the Solar Panel and using the "One Place" SP Controller and this is what he said. The board that is in the circuit behind the OP panel is simply there to prevent the current from going from the batteries to the SP. If you wanted to use the same board with more wattage one would have to modify/increase the diode size to take the heat of the increased wattage. He would make a small board that would contain three diodes but larger on heat sinks to dissipate the heat and run two leads from the original board with the diodes removed to the new board.This additional board could be mounted behind the OP, is not costly and easy to do.
Hope this helps -- Frank

CC38EL · 08-23-2007, 02:17 AM

Frank..thanks for the suggestion and the offer. I'm waffling between upgrading the board and just buying a featured controller.

About the wiring....do you (or your EE friend) think the wires from the current solar panel could handle the increase in amps from a larger, say 100 watt panel (increase of 6amps)? Or do you think you'd need to upgrade the wiring?

John_Canfield · 08-23-2007, 02:57 AM

A small panel (10-15 watts) puts out such little current that it can be safely connected directly to a couple of batteries with little danger of overcharging. The current is probably just enough to overcome the self-discharge rate of two batteries. Like somebody mentioned, there is usually a diode in series with the positive leg to prevent the solar panel from discharging the batteries. The problem with diodes is there is a 1.2 volt voltage drop across silicon diodes which is substantial in low voltage & low current situations. Schottky diodes are preferred with only a 0.6 V voltage drop.

On my coach, I think I could easily upgrade the existing 15 (or is it 10 watts) watt panel to 50 watts with little worry about the existing wiring. No way would I try 100 watts without upgrading the wiring.

In either case, I would buy a solar charge controller (inexpensive) to replace the original board.

FrankO · 08-23-2007, 05:28 AM

John,
When I was fixing my board I found the diodes were very warm to the touch. If one was to replace the std diodes on the board to the Schottky Diodes would the board still work correctly as it lowers the current from ~20.xV to ~16.xV for charging the battery and providing about 1.5V to the LED.
The diodes seem to be the weak link in the board IMHO.
Frank

John_Canfield · 08-23-2007, 07:59 AM

Frank - Having a diode a little warm to the touch wouldn't be a cause for alarm, but if you can't hold it comfortably for a couple of minutes, you might want to move up in the diode's current rating.

In looking around, I think a 1N5401 silicon diode would work well. It is rated for 100 volts and 3 amps maximum current and is very common and inexpensive.

If you can find it, a suitable Schottky diode would be a 1N5822 (data sheet) which is rated for 3 amps at 40 volts. I don't think there would be any problems caused by using the Schottky.

(I assume you are using the standard Winnie solar panel.)

FrankO · 08-23-2007, 01:48 PM

John,
Thanks for the info. I can't understand why the LED would go out after only being in use less than one year. LEDs typically last forever so I thought the board may have some how got a spike or maybe the LED was defective. I am using the std board that comes with the MH.I was just curious on how to protect against a future happening.
Thanks -- Frank

John_Canfield · 08-23-2007, 03:34 PM

I don't remember LEDs being particularly picky about their operating environment but they will burn out from too much voltage which I have personally demonstrated. You could have had a defective LED. I wouldn't loose sleep over this case.

TB-ONE · 08-23-2007, 05:00 PM

The three diodes are wired in series. Each has a voltage drop of .6 volts. Thats a total of 1.8 volts. The LED take a minimun of 1.5 volts for it to light and it is wired around the diodes. So if the Solar IN is 1.8 volts or more above the batteries the LED will light.

FrankO · 08-23-2007, 07:12 PM

I had a case where my batteries were close to dead when I covered to MH which is what started this whole issue. Is it possible that the Solar Cell was putting out say 20.xV and the battery was in the 9 to 10V range. Could that have burnt out the LED given what Tom/Sue said?
Thanks again for your input.
Frank
BTW John, I will not loose sleep over this issue, just my curiosity in full bloom. I like to understand all the ins and outs of the MH Systems for future troubleshooting.