How to unregulate solar panel

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

Should be ok. Is that the only connection into the regulator? Cable looks light but it should start the BCDC charging. How long are the leads? Can you make up short leads to see if there is a voltage drop issue?

I have just checked the specs for the panels I have. Each have slightly higher OC voltage between 21 and 22.5V but max power voltage is 17.5v, the same as the Projecta specs.

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

Should be ok. Is that the only connection into the regulator? Cable looks light but it should start the BCDC charging. How long are the leads? Can you make up short leads to see if there is a voltage drop issue?

Yes I could make up short leads but I don;t think there is any point. I have checked for a voltage drop, which there isn't and I'm only getting 16.5 volts right at the panel which is less than the 17.5 volts which is required.

On another note, a couple of people have mentioned issues with non-redarc panels with the redarc mppt regulators. I cannot find any threads on the issues. Is there a better phrase I should be searching for?

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

My panels are Chinese Bosch from two different suppliers and a Projecta solid panel. All with regulators bypassed and work ok. No experience with the folding panels however. As Bushy said fall back is to connect with the panel regulator direct to the battery but that is not the best option as you know.

I will have a Google.

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

I've connected it up again and measured the voltages.

Under no load I'm getting 20.3 volts with no drop over the length of the cable.

Under load I am getting a 0.4 volt drop. The measurement at the panel is still lower than 17.5 volts though so the voltage drop isn't the big issue here.

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

Not sure what is going on. Myswag has a couple of threads where people have used that exact panel with the regulator bypassed with Redarc BCDCs. The supplier did the bypass by fitting two Anderson plugs and charged $20 which to me suggests nothing special was done other than fitting the plugs. You measure 16.5V which is less than the panel specs. 20.3V is also lower than the 21V OC specified. Having said that I couldn't find anyone complaining about their folding panel not performing.

Weird.

All I can suggest is take it back to the point of purchase and ask to test it side by side with another tomorrow. Same conditions and see what you are reading.

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

You could going back to Redarc as they are aware of the problem as others
have had similar discussions with them, maybe they think if they just keep
fobbing people off the problem will go away?

From memory this problem has been discussed on Myswag, Explore OZ and
probably on the caravaners forum.

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

Not sure what is going on. Myswag has a couple of threads where people have used that exact panel with the regulator bypassed with Redarc BCDCs. The supplier did the bypass by fitting two Anderson plugs and charged $20 which to me suggests nothing special was done other than fitting the plugs. You measure 16.5V which is less than the panel specs. 20.3V is also lower than the 21V OC specified. Having said that I couldn't find anyone complaining about their folding panel not performing.

Weird.

All I can suggest is take it back to the point of purchase and ask to test it side by side with another tomorrow. Same conditions and see what you are reading.

Ive had confirmation that what I have done to unregulate the panel is correct. That came from Jet, the guy who does it for $20 on that thread. I think Ive pretty much given up. Ill probably hook up the projecta regulator again tomorrow and just accept the fact it isnt going to work as I had planned.

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

Not sure what is going on. Myswag has a couple of threads where people have used that exact panel with the regulator bypassed with Redarc BCDCs. The supplier did the bypass by fitting two Anderson plugs and charged $20 which to me suggests nothing special was done other than fitting the plugs. You measure 16.5V which is less than the panel specs. 20.3V is also lower than the 21V OC specified. Having said that I couldn't find anyone complaining about their folding panel not performing.

Weird.

All I can suggest is take it back to the point of purchase and ask to test it side by side with another tomorrow. Same conditions and see what you are reading.

A quick search found;
http://www.myswag.org/index.php?topic=46356.0
http://www2.pajeroclub.com.au/forum/...p/t-32614.html

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

I wasn't searching for your posts.

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

I wasn't searching for my posts either, a simple search of 1225 plus projecta was all that was required!

This issue has been discussed on a few other forums you need to get out more

Moral of the story is your setup may work well but that doesn't mean someone else won't have issues.

From what I have read on other forums the 1225 is not a very efficient unit in the MPPT department. The only real benefit of these units is they are a more cost effective solution than a stand alone DCDC charger and solar regulator setup. However your trading efficiency and redundancy for cost which is not a good thing if you do a lot of remote travel and your relying on your system to keep your food frozen.

One of the issues with MPPT type chargers is they require around 5V higher panel voltage than the terminal voltage of the battery, and there on around 1V higher than the battery terminal voltage to charge, with panels designed for 12V use it not unusual for the panel voltage to fall below these requirements on overcast or hazy days and in the case of the Projecta blankets it appears on sunny days also. Under these conditions a good quality PWM charger will perform better.

I have found that unless your going to invest in a good quality MPPT charger / panel setup designed to get the best from each other your unlikely to see any real improvement in charge current over a good quality PWM controller, and under some conditions A good quality PWM charger will perform a lot better.

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

On the basis of the specifications and that others have successfully married the two one of three things is occurring. Either the BCDC or the panel is not performing to specification or a combination of tolerance is stopping it working. If 100% of folding panels failed to work then you can lay the blame on the BCDC. As others have no problems it is not a generic problem with the BCDC despite what others may say. Your measured voltages from the panel are lower than specified. So to confirm the panel is working you should sit it side by side with another and test both with your multimeter. That will discount whether there is an issue with the panel.

On my 120 which had a different charging system That I would never use again I plugged the output from the solar panel regulator directly onto the auxiliary battery. Never had a problem and I left it connected whether the engine was running or not. I had some advice later on that having 14+V on the output side of the solar regulator could damage it. Not sure why as I would have thought that it would sense a charged battery and shut down. Anyway I had no problems but it might be prudent to set the infeed up through a relay should you go that way.

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

He's getting 20V open circuit, allowing for tolerances in the panel and his volt meter that sounds pretty good to me. He is also getting 16.5V under load which depending on the load on the panel could be quite normal. Say others had success with the same panel and unit doesn't put the blame on the panel, others have also had the same issue, so it could be the panel or the charger or most likely a combination of both. The setup is probably marginal at best and if either unit is a little off spec the setup doesn't work

It would appear to be a simple compatibility issue, the solar panel works ok by itself with its own regulator so it does what it should and appears to meet its own specs, ie produces 20V unloaded and should activate the 1225. It however doesn't work with the 1225. I suspect there is more to getting the 1225 to start charging than the input voltage being 17.5V, it probably needs to see 17.5V for a period of time, it then most likely starts to charge and observes the voltage, if the input voltage falls below its minimum requirement when load is applied to the panels it turns off and goes through the wait process again.

We therefore get into the grey area that if Redarc haven't tested it with all panels then they should either state clearly that the unit may not work with all panels rather than just put a note in the manual stating needs a minimum of 17.5V to start charging, or preferable give a list of panels it has been tested with.

It may not be just the projecta panels causing issues, I have seen other post indicating the unit won't work with their existing panels but they don't state what brand the panels are.

It states in Redarcs glossy for the 1225, "Solar input voltage range 9-28V, suitable for 12V panels only" that is very misleading as clearly the unit will not start charging unless the voltage exceeds 17.5V, and most likely won't continue to charge unless the panel voltage remains 1V above the battery terminal voltage under load, the load placed on the panel is dependent on the charger.

There are a lot of cheaper 12V panels out there that will most likely not work with this charger.

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

Has anyone actually asked Redarc?

The internet and facebook are very informative places, unfortunately some users grant themselves an unrestricted license to post whatever they want (I hold 3 of these licenses).

As a very recent purchaser of one of these units I admit I have a vested interest in knowing more.

I have every respect for Redarc as a quality company and they have been a valued supporter of the annual GTG for some time. I have asked them to have a look at this thread and provide some feedback.

IMHO, they would not muck around making the MPPT only function with their panels. It would amount to some serious trade practices issues.

Anyway, I wait to hear from them.

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

I don't think you said anything different to what I wrote as far as the possible causes go. The one thing that stands out is that the panel voltages are lower than shown on the spec sheet so a comparison with another panel would put to bed that it is ok. Similarly trying a different BCDC or different panel on that BCDC will see if there is a problem with the BCDC.

Needs more testing less speculation.

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

The only voltage you can say is lower is the open circuit voltage, as you have no
idea as to what load the charger is applying to the panel therefore it is impossible to
say if the panel meets its maximum power specifications without doing a proper test
as you wrote, nor do we know how accurate his volt meter is!

I'm sure if he contacts Projecta they'll say the blanket is within tolerance, Redarc will say the 1225 is ok, simple fact is the blanket works ok with its own regulator, the Redarc with some solar panels, in this case the two won't work together.

Trying a different panel achieves nothing just might indicate the charger works with a different panel as it puts out a slightly higher voltage this does not necessarily indicate the blanket he has is faulty in any way. Same for a different charger, all electronic devices have tolerances, another charger might work fine on the same panel, doesn't mean the charger he has is defective, just indicates the setup is marginal, most likely both devices will operate within their design tolerance.

Simply fact is the combination of the panel he has and the charger don't work, the panel manufacturer makes no claims the panel will work with the Redarc device, Redarc state suitable for use with 12V panels, unless it doesn't work then they back track only guaranteed to work with their panels but as they don't actually state that in the glossy or owners manual one could rightly ask for a refund as it doesn't work as advertised.