How to unregulate solar panel

[danestead Junior Member Find all posts View Profile Close danestead]

Hi all,

I have just wired up the solar relay for my Redarc 1225 BCDC charger however I'm having issues with the solar input. It appears to be an issue from the solar panel end.

I have a 120w folding Projecta panel which has a PWM regulator on it. I thought it would be as easy as unscrewing that regulator and rejoining up the wires. Under no load I am getting 20 volts. When connected up to my car I am getting about 16.5 volts at the panel under load. My Redarc 1225 needs 17.5 volts from the panel to charge. Lex at Redarc advises that it looks like there is a problem with my solar panel (which is brand new) as it should be regulating to in the vicinity of 18 volts.

Have I bypassed the Projecta PWM regulator correctly (it isn't connected at all now) or do I need to unstitch the fabric on the panel to do something to the wiring inside?

Cheers,
Dane.

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

Redarc strikes again, what they don't tell you is redarc DCDC chargers are designed to work with Redarcs solar panels, it is not your panels it is the Redarc!

Many are complaining of similar issues.

Cheers
Leigh

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

Redarc strikes again, what they don't tell you is redarc DCDC chargers are designed to work with Redarcs solar panels, it is not your panels it is the Redarc!

Many are complaining of similar issues.

Cheers
Leigh

Really? I have successfully used three different brands with my BCDC chargers.

Have you wired up the changeover relay as per the Redarc site?

[danestead Junior Member Find all posts View Profile Close danestead]

Redarc strikes again, what they don't tell you is redarc DCDC chargers are designed to work with Redarcs solar panels, it is not your panels it is the Redarc!

Many are complaining of similar issues.

Cheers
Leigh

I was under the impression that a solar cell is a solar cell and they all create a certain amount of voltage/amperage. Is this not the case? I do understand there are different types of cells though like the monocrystalline, and the other floppy panels like Redarc's blanket but I didn't think that would make a difference to voltage.

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

Yes really, this issue has been widely discussed on other forums, he also wrote he is seeing 16.5V under load so clearly they regulator has been removed from circuit.

[danestead Junior Member Find all posts View Profile Close danestead]

Really? I have successfully used three different brands with my BCDC chargers.

Have you wired up the changeover relay as per the Redarc site?

Yes I have, as best to my knowledge. The problem lies right at the panel as when under load it is not producing the 17.5 volts the redarc requires to activate the charging.

I have emailed RV Power Solutions to find out if I have unregulated it correctly because I think that is the most likely cause. Theo/Jet there unregulates them all the time and will know the answer I'm sure. I get the feeling there is more involved than just unscrewing the regulator like I have done because I remember reading that on the newer version Projecta Panels, the unregulating is a little more complicated or time consuming. Just waiting on a reply from him.

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

Post up pics and the model of the solar panel. What you did sounds right. With one panel I had to open up the junction box on the solar panel and remove the guts but you can usually see the panel wires. 20V OC should be ok. Post up a pic of the changeover relay if you can still see the wiring colours to the BCDC.

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

I hope I'm wrong but probably a simply a case of your panel not being able to generate enough voltage when the charger loads it up.

[Drift Member Find all posts View Profile Close Drift]

Bypassing the regulator should work for you provided your connections and cable are adequate. Have you measured the voltage at the solar panel end to see how much volt drop you're getting?

[danestead Junior Member Find all posts View Profile Close danestead]

Bypassing the regulator should work for you provided your connections and cable are adequate. Have you measured the voltage at the solar panel end to see how much volt drop you're getting?

I have been measuring it right at the panel where it used to wire into the old PWM regulator. I have also measured it at the end of the ~5m leads and there is no voltage drop.

[danestead Junior Member Find all posts View Profile Close danestead]

The top photo is the Projecta 120w folding kit/panel. The bottom photo is the back of the regulator which sits in the front pocket of the panel. 2 of the leads are connected to it in that photo however when I had it connected up to the car I connected those leads directly to the others in the photo, completely doing away with that regulator.


https://fbcdn-sphotos-a-a.akamaihd.n...ee244afb36a446

https://scontent-lax3-1.xx.fbcdn.net...a3&oe=57353C53

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

The specs for the blanket show max power at 17.5V so they should work, but from another site:

"Hello all,

I have a Redarc BCDC1225 installed providing charge to a battery under the rear seat of my 2013 BT50.

I have tried connecting 120w Projecta folding panels (unregulated) to the Redarc but get no charge. Read the manual and says needs 17.49v is this correct? My watt meter indicates 17.29v so is the solar not giving enough oomph?"

Really I can't see why the Redarc needs such a high voltage to start charging.

[Bushbasher Out of control poster! Find all posts View Profile Close Bushbasher]

Why not leave it as is and connect directly to the battery that needs the charge - your auxilliary. I'm sure the panel manufacturer is happy with you modifying the product.

[danestead Junior Member Find all posts View Profile Close danestead]

Why not leave it as is and connect directly to the battery that needs the charge - your auxilliary. I'm sure the panel manufacturer is happy with you modifying the product.

I want to take advantage of the MPPT regulator that the Redarc 1225 has rather than the PWM regulator fitted to the panel. You can research the power advantages of the MPPT. All I have done is unscrew the 4 screws in the second photo I posted above. TBH, it's my choice whether I modify the panel or not and not the manufacturers. Obviously I'm not going to try do a warranty claim if I stuff the panel.

[danestead Junior Member Find all posts View Profile Close danestead]

The specs for the blanket show max power at 17.5V so they should work, but from another site:

"Hello all,

I have a Redarc BCDC1225 installed providing charge to a battery under the rear seat of my 2013 BT50.

I have tried connecting 120w Projecta folding panels (unregulated) to the Redarc but get no charge. Read the manual and says needs 17.49v is this correct? My watt meter indicates 17.29v so is the solar not giving enough oomph?"

Really I can't see why the Redarc needs such a high voltage to start charging.

I've just heard back from RV Power Solutions and he seems to think it is an issue with the Redarc like you mentioned above. I'll do some research and see if there is a work around. If not, it's been $150 waste of money and 5 hrs installing the solar relay.