Solar Panel/Sargent EC328/12V Electrics Fault

As I have highlighted in another posting I have recently had fitted a 100W Solar Panel to my Marquis Lancashire (Auto-Sleepers Nuevo) and had it plugged in to the Sargent EC328 Power Control System which has an inbuilt solar regulator which charges both the leisure and the vehicle batteries.

However in bright sunlight and when both batteries are reasonably well charged the 12 volt electrics have been regularly turning off especially if no equipment (lights, taps, fans or TV) is turned on. It appeared that the solar regulator was not shutting off its charge in such circumstances and that some protection mechanism was coming into play to prevent the batteries being overcharged.

After some liaison with the Sargent Technical Support People it was established that the control panel on my van was fitted with a solar regulator which is no longer used as it is less sophisticated than the latest version.

Although my motorhome is out of guarantee Sargent very kindly sent me without charge a full EC328 Exchange Unit with an up-to-date solar regulator and this has now been professionally fitted in place of the original.

I had anticipated that all would now be well but to my frustration the problem remains. It is possible that both control panels are in some way faulty but I somewhat doubt it.

Incidentally the system is designed to accommodate solar panels up to 120W so it would seem unlikely that the solar panel is too "powerful" for the regulator.

I wonder if any of those with more technical knowledge than me may be able to indicate what is likely to be causing this relatively minor but annoying problem.

Frustrating for you, and bad news for me, as I was just about to order a 100W panel to connect to my EC328.

As I see it the problem is that the only "active" components in the system that you have installed are all within the EC328. If the people who designed and manufactured the EC328 can't figure out why it's happening and how to resolve it, I can't see how anyone else can.

I guess the only thing that might take this forward is if you can document a precise, reproduceable set of conditions that cause the unit to cut out every time they occur, and feed that info back to Sargent. It might be worth considering buying several cheap voltmeters like these:

[You must be registered and logged in to see this link.]

and wiring them up temporarily across the solar panel, the leisure battery and the vehicle battery so that you can see in real time what's actually happening just before it shuts down.

Thank you Mojo and Peter for your helpful guidance. I will experiment appropriately and post the outcomes in due course.

Before I have had an opportunity to follow the testing advice given to me in this thread I have been away for the weekend in my motorhome.

My experience over a couple of days has shown that not only has the new EC328 unit not solved the problem outlined previously but new malfunctions are now apparent.

The 12v system which was previously turning off when not under load is now cutting out when under load. This occurred quite a few times between Saturday and today including when I was watching television.

Very strangely when the 12v goes out the light below for the pumps remains on and the taps continue to work.

In addition the 12v is now turning off when on mains charge. I am not sure whether when on mains charge the input from the solar panel is meant to be shut down.

Unexpectedly when I follow the advice given on this thread to turn on the vehicle battery light to the left and draw 12v power from that source the problems apparently disappear whether on mains or not. Again I am not sure in these circumstances the whether the solar panel and/or mains input are still charging both the leisure and vehicle batteries but my observations seem to indicate that it is only the latter that is receiving current.

As my problems have increased since swapping the original Sargent EC328 for the replacement supplied do you think the above is indicative of the replacement Sargent unit being defective even if it now has a more up-to-date solar panel regulator.

Is it still essential to disconnect the solar panel to see the effect on the 12v electrics or should I ask Sargent to replace the replacement unit before investigating further given all the problems highlighted above.

The thoughts of those much more knowledgeable in this field is awaited with interest.

Wearsider wrote:
Unexpectedly when I follow the advice given on this thread to turn on the vehicle battery light to the left and draw 12v power from that source the problems apparently disappear whether on mains or not. Again I am not sure in these circumstances the whether the solar panel and/or mains input are still charging both the leisure and vehicle batteries but my observations seem to indicate that it is only the latter that is receiving current.

That's correct - when you switch from Leisure to Vehicle battery on the control panel, power is taken from the vehicle battery and the mains charger charges it. Leaving aside the solar input, you are taking the leisure battery out of the system.

This implies to me that the problem lies with the connection to the leisure battery. If you have not already done so, I would be taking a very close look at the connections at the battery itself, and also checking that the connection to the chassis is good. I've found in the past that bad earth connections due to corroded or loose chassis cables can create some rather odd-looking symptoms.

Having said that, it is of course possible that the problem with the connection to the leisure battery is within the EC328 itself...

Thanks again Mojo and Peter. I will proceed along the lines that both of you suggest and report back in due course. Michael

In haste to acknowledge your early morning posting Peter I neglected to focus on the questions that you posed.

My solar panel is connected directly into the Sargent solar panel input connector on the bottom of the PSU using Sargents dedicated lead specially purchased for the purpose.

The solar panel was professionally installed but to the best of my knowledge has been wired correctly.

Whilst my PSU is the EC328 the control panel corresponds in appearance to that of the EC325 although I am not sure whether the differences are functional or cosmetic.

I have checked whether any other 12v equipment is operative when the 12v light goes out but the pump light remains on and the taps continue to work. As far as I can tell everything else is "off".

This afternoon I had the solar panel disconnected and will spend the next day or two checking that everything is working without faults before having it reconnected and further checks carried out in accordance with the suggestions posted earlier in this thread.

Wearsider wrote:
Whilst my PSU is the EC328 the control panel corresponds in appearance to that of the EC325 although I am not sure whether the differences are functional or cosmetic.

Does your control panel not look like this one?

[You must be registered and logged in to see this link.]

If not, are Sargent aware of this? From their website, I believe the new one (as in the link above) is compatible with either EC328 or EC325 power units, but I don't know whether an older style control panel will operate the later EC328 properly. Mind you, it would seem extraordinary for you to have been fitted with that combination in the first place if not...

No mojo my control panel is not like the one you provide a link to. It is definitely the EC325 one. I mentioned it to the guy Sargent and he implied that it was not an issue.

Thank you Peter for your further observations on the control panel fitted to my motorcaravan.

Sargent have been provided with precise details and have confirmed that although the front cover differs from manufacturer to manufacturer mine has the correct circuitry.

I am going to leave my solar panel unconnected until after the coming weekend so I can fully check that everything is working as before before investigating the problems that apparently only arise when the solar panel is connected.

I will post again next week as matters progress.

Michael

Michael

This post makes very interesting reading. I have a Nuevo ES which I picked up new in March. It needed a few things sorted so had it back to Marquis a couple of weeks ago. One of the problems I highlighted was that I didn't think the solar panel was charging the batteries. The technician confirmed that the plug from the solar panel had not been fully inserted. The solar panel was now charging. However, within a couple days the 12 volts system started to switch off, seemingly randomly.

I did some investigation and below are my cryptic notes for your information. I'm currently awaiting a call from Marquis to discuss my findings.

Any comments are welcome.

Ps.......really like the motorhome.

Cheers, John

12 volt problem

Nuevo ES
New March 2013
Supplied by Marquis

Control panel
EC328S.    v2.20
Board serial number 00056753

Symptoms

12 volt switches off, control panel light goes off
Random - fails after a few seconds or can last overnight
Pump light stays on
Leisure and vehicle batteries both showing good level of charge

Fault appeared after van had been to Marquis to have a number of issues addressed.

I pointed out that the solar panel did not seem to be charging the battery. The technician confirmed that the solar panel plug was not inserted correctly into Sargent 382 psu. Since then the solar panel has been charging.

Actions

Checked all connections
Disconnected Sargent 382 control panel multiway plug for 30 seconds and reconnected

Could be related to:

1. Faulty sensor e.g. battery low sensor, temp sensor or other.
                               
2. Control panel software corrupted

3. Charging process

It does not fail overnight when not connected to mains but had failed once the sun had risen. Also, did fail during sunny day when charging from solar panel only at approx. 1.5 amps or when charging from mains.
Covered up solar panel during a sunny day without being plugged into mains and it did not fail.
Left overnight plugged into mains and solar panel uncovered did not fail until sun had risen.

Conclusion

Fault is related to charging from solar panel. Suspect solar panel dual controller is faulty.
Need to know if there is any adjustment can be done !!!!!

Your posting John makes most illuminating reading.

Your problems seem to be a mirror image of mine.

Also my control panel is exactly the same model as yours with the same software version.

My solar panel is a Cleversolar 100W unit and I had some thoughts that it might be overpowering the dual solar panel controller.

Accordingly I would be interested to know the wattage of your solar panel.

I am sure your vehicle will be fitted with Sargent's latest solar panel controller within the EC328 psu (Google EPIPDB-COM) which does allow the type of battery to be specified (sealed gel, or flooded), the setting of the percentage split of the charge that should go into the leisure battery and the vehicle battery (90%/10% or say 50%/50%), and permits charging frequency (Hz) adjustment.

If all else fails I will certainly experiment with changing these variables to see if any settings solve the problems .

That all said the fact that both of us are experiencing similar issues to my mind points in the direction of some part of the EC328 equipment being the culprit rather than any wiring issues being the cause as the latter would seem to be too much of a coincidence.

If I may I will forward on your posting to Sargent's Technical Support Specialist, Craig Foot, (craig@sargentltd.co.uk) who I am liaising with in the hope that a solution can be found.

Michael

Yes, it is very interesting that we both have the some symptoms.

I have not been able to work out how to change the settings on the solar panel controller re gel, sealed and flooded.

I'm happy for you to forward me findings to Sargent. I may be speaking to them soon myself.

Let's hope we see resolution soon

Btw my panel is 40 watt, supplied by Autosleeper.

Phil from Rhino installs put my solar panel on and when I asked why he wanted to wire it separately rather than through the Sargent unit, he said they had no end of problems. So I took his advice and have had no issues at all with it.

Reading the above, I can now see why........

Peter

Like you I would to see a circuit diagram but given that it's probably microprocessor controlled it probably won't be much help. I've had a look at the solar panel controller it's a sealed unit.

Enjoy Hawes.......I was there last week for the first time.....great location......and coincidently it was while on that site my 12 volt gremlin came on board......


Cheers, John

Thanks for the research and useful info. For some reason I had expected Sargent to buy in a solar controller chipset and build it onto their board, not to buy a complete box and build it into their box! However, given that almost the entire Chinese solar industry is state-subsidised, I can understand why they took the route that they did.

It would be interesting to know if any installers of retro-fit panels are aware of the settings that may need to be made on the solar controller. The Chinglish manual says what the default settings are for most things, but not (as far as I could see) what the default battery type is set to.

It also makes me wonder if it is possible (at reasonable cost) to get the optional MT-1 display panel for the EPIPDB-COM so that you could see the status of the controller without having to take the cover off the EC325/328.

Peter Brown wrote:
With respect to bypassing the Sargent unit with the solar panel, that was ok up to the 325.  However the 325 and 328 chargers are able to generate high voltages for fast charge and would likely damage the external solar regulator.

Peter

Hi,

It is wired through a proper controller, just not the Sargent one. It must be the same on countless other vans... or have I missed the point yet again? Thanks

Peter

I've had similar thoughts.......I wondered if there could be some electrical noise causing interference......

I've just had a call from Marquis. Apparently they have seen this before on one unit at Preston. The problem is that the control board should cut off the solar panel once a certain voltage is reached. If it doesn't cut off the unit (not sure which one, the solar controller or other sensors in the psu, I think the psu) senses the over voltage and cuts off 12v supply to protect the circuitry.

They are going to speak to Sargent and ask for a new solar panel controller to be sent to me which I have offered to fit.

I'll keep you posted.

John

DuxDeluxe wrote:

Peter Brown wrote:
With respect to bypassing the Sargent unit with the solar panel, that was ok up to the 325.  However the 325 and 328 chargers are able to generate high voltages for fast charge and would likely damage the external solar regulator.

Peter

Hi,

It is wired through a proper controller, just not the Sargent one. It must be the same on countless other vans... or have I missed the point yet again? Thanks

The issue is specifically with the EC325, which is unlike any other controller in common use in motorhomes, in that it has an "offline charger", where the leisure battery is disconnect from the habitation 12V while it's being charged. This is fine where the solar controller is built into the EC325, as it can disconnect the solar panel from the leisure battery when it's charging it.

If you use a separate solar controller it has no way of knowing when the EC325 is fast charging, and that stage - which can take the battery voltage up to 17V or more - is outside the voltage range of most, if not all, solar chargers, which never expect to see a battery voltage higher than 15V.

The "offline charger" mode had the advantage of quicker leisure battery charging with the EC325, but it was dropped in its successor, the EC328, which has a normal "online charger". I think this was because it created more problems than Sargent had anticipated, but that's just speculation on my part...

I have read with considerable interest all the postings today on this issue.

John has been informed by Marquis that they know what the problem is and the diagnosis fits with my non-technical suspicion that a protection mechanism was coming into play and turning off the 12v system.

That said it could turn out to be a false dawn as I have recently been supplied with a full replacement EC328 psu in place of an earlier model and instead of solving the problem, problems have increased. My earlier postings set out the full story and are perhaps worth re-reading.

Whilst I have not the slightest doubt that you John have all the technical ability to fit a new solar panel controller if the vehicle is still under guarantee I would in your position insist upon Marquis doing the work so the responsibility is with them to sort out the problem if it persists.

However I will certainly factor in all of Marquis have said in my own quest to solve the problem with Sargent's assistance supplemented with work by my own auto electrician.

Incidentally Sargent have now confirmed to me that when on mains the solar panel continues to also charge the batteries. This would tend to confirm my suspicion that when the 12v system turns off it is the solar panel input that is triggering it rather than the 240 volt energy source.