Solar panels

OK. So, who is going to dare to offer up a theory on the cause of the losses in the original set up.

We could start with the cable from the Solar Panel,  a small core diameter, length of 12V Twin Auto Cable. No doubt this puts the set up on the edge of recommended maximum loss. However using this cable to connect the panel to a decent regulator gives reasonable performance.

The Sargent Regulator is definitely extremely inefficient but even that tries to work if the sun is not too strong. In no way am I going to mess about testing that regulator performance with it bypassing the EC700.

When I first started on this road I was misled, I understood that the EC700 had solid state switching, that would be virtually lossless. I was assured by AS that the Smart switching has no loss, because it is switched by a relay. Oh really!

Using some detective work, it seems that the Relay used is described by the manufacturer as a Micro Relay. When I built my Two Stage Controller for Wind I used a huge two pole Automotive Relay with the contacts in parallel to minimise contact loss.
This Micro Relay has an off the shelf specification for Initial Voltage drop at 10 Amps of 30 to 300mVolts. The highest figure stated 300mV is again on the edge of maximum loss for a complete solar installation. So we now have double the recommended loss in the system. As the Smart changeover is likely to be done at low currents the contact resistance will start to increase with use.

I don't know what else goes on under the dreaded hidden circuit board. Someone apparently in the know said that the PCB print on an ECXXX would not take the current of an extra solar panel. I don't doubt that, so that also will introduce loss. In my two stage 1980's controller I used PCB tracks 4cm wide to avoid loss.

The above is related to the lack of solar input efficiency. What about the loss encountered during use and when the EC700 is in Shutdown.
Sargent say the drain of the EC700 in use is 200 to 300mA. Quite a lot of current when the very inefficient solar controller with the attendant losses is putting a shallow charge into the Leisure Battery, if you want your Vehicle Battery to be topped up too then you must let the 'smart' selection go ahead or manually deprive the Leisure Battery of some vital current.

Sargent say that the Shutdown current is 100mA. I strongly suspect that the EC700 Shutdown button does nothing of the sort. I suspect that it is merely in a standby mode with the Microprocessor still running. Until someone starts to tell us the truth it will have to remain suspicion. Why do hundreds of owners put up with this.

Mr Marconi, I suspect the reason that 'hundreds of owners put up with it'  is because 99% of us do not have your obvious expertise/knowledge of these things, if the manufacturers tell it will do/not do so & so, we tend to believe it. 
On my last AS I fitted a 100w panel & a very nice Sun Saver Duo control system, I thought it was the bees-knees, & simply believed the hype, but of course, it might have been crap, it did however, always keep everything charged up. 

Marconi
Myself would like to say well done to what you have said here
The problem you get only a small number of people that buy motor homes have a back ground trade skills on electronics and take the word as Autosleeper’s say to be true.
With out this forum and been able to see that others are having the same problem making my self try to do some mods to make my van useable all year round .with how I was spoken to at the nec show last year buy a Autosleeper worker said it all .when I looked to see any changes they had made on my van and I said that’s what I am doing then started saying the problems as you have said and he said not in a nice way nobody else  has that problem. So maybe we should all start sending all are faults for them to see. As just the electrics are not fit for purpose as like my fridge not been fitted to legal speck

marconi wrote:. Why do hundreds of owners put up with this.

modelman

That was not meant of a criticism of other owners. Maybe: Why do hundreds of owners have to put up with this. would be more suitable.

There is another factor comes into it. As an I owner I have felt it better not to say too much about the multiple problems and remain very polite whilst begging on your knees for warranty work to be carried out. Otherwise the mat may be pulled out from under your feet.
This Solar problem I have completely given up on, the proposed courses of action would have taken a long time to fit and try, and one alternative would have cost me money with no guarantee of quality.

Again I have resisted the temptation of a thread. Dear Auto-Sleepers Employees.
 
One of the best things you could do whilst sitting at home avoiding Covid 19 is to thoroughly read the AS Forum. You may learn an awful lot about the continual mistakes that are made and repeated, the bad workmanship, the lack of skill and understanding of your products, the fact that the customers know they are told untruths, the insults that are sometimes thrown at us, and please publish the contact details of your CEO, we don't write to him in order to get rude replies from the Warranty Parts Manager. I think the future survival of the Company depends on it.

Yes, its a great shame isn't it, these things are not cheap either, & whilst I think its fantastic to have all this very hi-tech, ( to me anyway )  stuff, it ought to work properly, maybe my old basic lectrickery model isn't so bad after all, at least it all works.  

I wonder sometimes if manufacturers don't field-test new products enough & get them onto the market too soon, rather than loose sales to the competition.

I have never had a problem with my Warwick, only mod was to fit a 120w solar panel and wire it directly to Sargent solar I/P.

I think some people are getting a bit technical, but that is just my view or have I been lucky with my set up, as others have said " It works for me"  I expect some comments
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Richard

We're your PCB tracks really 4cm wide or did you mean 4mm?

Marconi
as you are saying you should always give the dealers a chance to put a fault right for the manufacturer before taking any other action.
like your self I have a list of faults and will be giving the dealer and auto sleepers a chance to put right and hope after the first fault I found after driving home from collecting my van from new  tried to say I had caused the problem until I replied and explained my position in the motor trade and then they asked if they sent myself the part could I fit it as I was now broken down .so I would hope they don't try it on again.( the other 99 % would have been charged for the problem I had.)
 to send a message as you have said would look best coming from an admin person here.
I always try and say to my self the reason I always have so many problems is when its your trade you find faults others would not find a problem (ref  the solar twin wire being to small the wire that plugs into the controller is even smaller on mine so like you have said about above is a good example her )  as you have said is just part of the reason is not fit for purpose and  yes this is on my list

inspiredron wrote:We're your PCB tracks really 4cm wide or did you mean 4mm?

4cm definitely, if you want to carry current with no loss you need copper.

glyne lock wrote:Marconi
Myself would like to say well done to what you have said here




So maybe we should all start sending all are faults for them to see. As just the electrics are not fit for purpose as like my fridge not been fitted to legal speck

Totally agree glyne. I once worked for Honeywell in a dept that had access to all the British Standards. At the time I had an AutoSleeper LT28 and the fridge didn't work on 12v even with the engine running. I looked up the British Standards for caravan wiring and found, so far as I remember that the 12v supply to a fridge should be a minimum of 4mm csa in a motorhome, larger for a caravan because of the longer cable and connectors. My LT28 had 2mm csa as far as I recall. I rewired it with 4mm cable, and used a blade fuse in line instead of the one A/S used. Remember this would have been about 1989, and my LT28 was at least ten years old at the time, so I am not in this paragraph accusing A/S of still doing it - though I wouldn't be surprised if they are.
Anyway my point is that I got hold of the BS specs for caravan wiring / tow bar wiring, and went round the caravan show and not a single one of the caravans used wiring to the BS spec. That standard 7 core cable they use is not to BS specification.
Like marconi I used to work in a R&D electronics lab and learned a lot about things like contact resistance and the different specs of different makes of the same electronic component. I made myself an electronic ignition for my car and had to use MIL spec components in some places.
So it is just possible that A/S are making stuff to British standards, but I suspect not. I also suspect that they are telling Sargent what they want the electrics to do, and possibly Sargent are sufficiently clever to design a good product. I then suspect because I have heard it from a supplier of another electrical product, that A/S then tell Sargent the price they will pay for the electrics and Sargent, poor chaps, have to either forgo the business or make what they know to be a sub-standard product. I was told by a Karcher salesman for example that Karcher make a sub standard product for B&Q because B&Q tell Karcher how much they will pay for a pressure washer. The washer you get from B&Q is inferior to the one you will get from a pukka Karcher dealer, and you buy it from B&Q because it is cheaper. It has a plastic piston instead of the precisely milled stainless steel one in the proper machine.
Then, you might say to yourself what I have been thinking these last few days. That is this: A/S make vans deliberately geared towards people who go to camp sites and plug them into the mains. Enough said: therefore the vans are designed to run off mains, not solar panels. They put solar panels on so that the salesman can say 'look, it has a solar panel so you don't need to stop at a camp site'. "It has a reversing camera" - but the fact that it is a seriously inferior one is overlooked by the salesman and the purchaser.
I reckon that Sargent know a lot more about electrics than A/S do. So it is standard practice for A/S to respond to people with awkward questions either 'yes, it does that', or 'go and ask Sargent'. Sargent will then defend their business because they don't want to lose the A/S business.

Marconi - a simple response to your question is you or any of us could do with the solar wiring what I did with the wiring to my fridge that I mentioned. Start at the panel and measure the voltage. Go to the end of the two core auto. cable and measure the voltage, see what the drop is -although of course current would have to be flowing. Run your voltmeter as best you can through the pcb, the relays and so on and observe a volt drop at each connection point or component. Measure it as it emerges from the electrical box on its way to the battery, and finally measure it at the battery. This is what I did with my non-working fridge, found several volts dropped along the way and that is why the fridge didn't work.

marconi wrote:

inspiredron wrote:We're your PCB tracks really 4cm wide or did you mean 4mm?

4cm definitely, if you want to carry current with no loss you need copper.

The cable from the solar panel should be 4mm csa, (which it isn't on an A/S from the factory) and I suspect that 4cm pcb track would be about the same. A tad impractical though! You would have a HUGE pcb.

gassygassy wrote:

The cable from the solar panel should be 4mm csa, (which it isn't on an A/S from the factory) and I suspect that 4cm pcb track would be about the same. A tad impractical though! You would have a HUGE pcb.

My Controller must be in the loft somewhere it was mounted in a standard 6x4 inches box, you only need two short tracks, shortest path possible, for the high current DC pos. & neg. the Relay sits across their area, In and Out terminals mounted on the board, alongside is the normal control electronics, normal size tracks, Voltage Comparator chips etc. Your right the track size was calculated not guessed although the 4cm is a guess from memory and it depends on the PCB foil thickness spec.

At the time at work we were building our own design Analogue Single and 3 Phase AC Mains to DC Variable Speed Motor Controllers some all on a PCB, some in a cabinet 6ft tall, Loads of Current Loads of Power.

Today if I wanted to run the Wind Generator I would use a commercial MOSFET Controller.

Unfortunately I suspect that some of the choices that A/S make on cabling are forced on them by the suppliers - the solar panels that I've bought in the past have come supplied from the factory in China with wires pre-terminated that have inadequate CSA unless you have it right next to the battery.

You can (and I did) open up the terminal block on the panel, cut out the silicone sealant, desolder the thin wires and solder in decent ones - but it takes maybe half an hour to do it properly, once you have re-sealed the terminal block up. For A/S that is probably time (=money) that they don't see as worth spending, when it makes only a relatively small difference to the efficiency of the solar system (maybe only a few percent, overall).

In my experience they (and most other converters that I've looked at in detail) put similar economies into the cabling of their split charge circuits. The cable CSA from the factory is generally barely adequate, but it makes installation easier and quicker - and probably saves a few tens of pence in material cost as well! Though in the case of split charge cabling there is an argument (made here before) that there is a genuine benefit to having thinner cable on that circuit than might otherwise be desirable.

But... I don't expect the situation to change, because cost (of material or of installation manhours) will almost always win out, and most owners simply won't be aware of the issue anyway...

A quick look at the web confirms that Sargent systems in for instance Swift suffer the same problems.

A-S buys a system off the shelf, with the wiring loom with excess under rated cabling, with latest 'features' that the Salesman can waffle on about and weave more lies around his misunderstandings.
 I don't think A-S specify anything, they sometimes "go it alone" on an add on with disastrous results, just look at your Truma INet box, it sits and wastes power, you can see remote data, but the real function, remote control, doesn't work, they couldn't interface it with the Sargent controls, so they hide that in the menu.

Please note amendment to quote above.

I will accept that rather odd altertion Peter although it is still a glowing failure. It should not have been released and sold to the purchaser as a feature.

Testing seems to be an anathema to A-S.

It begins to look as if my Nuevo, a 2015 model is better than the new ones. Cam chain not a belt, normal alternator, not an intelligent one, no blue stuff to have to put in the tank, Sargent 328 which sounds as if it is better than the new ones, no iNet thingy which I hated the look of as soon as I saw it. Even if it doesn't have metallic contact switches my 2015 sounds a bit better than the latest. I'm beginning to like it more! and if I do change it may well be to a 2015 EB model which I think I might have bought in the first place if I had bothered to diligently search the different models.
. . . . mind you I wonder if you can change the standard rear view camera for one that works on an EB model . . .

An Englishman takes time.

I keep referring to the shallow charge that the Sargent Solar Controller and EC700 combination supplies to your batteries.

At last I have got round to producing a better Graph (Bar Chart) of the solar performance of our Nuevo in 8 hours of real sunshine in January in Spain.

I spent a whole day taking readings of the Solar Current every half an hour.
The original graph plotted the current with voltage readings added, and I tried to represent the On for a fraction of a second, Off for 6 seconds behavior which Sargent describe as 'PWM like regulation' by showing a reduced number of pulses on a small piece of paper. This was not the clearest way to display data and it certainly shocked AutoSleepers into total silence.

The Bar Chart below shows Current I against Time T.
The Pulsed period between 10:30 and 15:00 are the peak hours of sun. Other motorhomes and my portable Solar Panel which I purchased later were reaching Float charge by 10am.
I am being overgenerous on the chart in representing the result of the Controller completely dropping any charge for 6 seconds, then pulsing very briefly and dropping the charge again for 6 seconds, during this period of four and a half hours. I have represented the results as if the pulse lasts for half a second it doesn't.


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Some offered the opinion that the battery was fully charged by 10am, this is not so, in that the  battery started at 12.2 Volts and at the end of each solar day there was very little usable capacity. Now we know that the EC700 itself uses 7.2AH daily and observing the Chart above there is little surprise that there is nothing left for leisure.

In the UK the On Off pulsing is not as prevalent due to the inherent lack of sun, however the inappropriate pulsing was observed with my Nuevo and another which is being monitored at this time. The daily charge will appear to be better in the UK but is still shallow due to the absence of a full charging Current and Voltage ever being reached before the pulsing starts.


Below is the Voltage Bar Chart for the same period.

The brief increase in Current and Voltage as the sun goes down is bizarre. The 13 Volt levels and the 13.5 Volt peak are only momentary levels in Voltage at the time of the pulses, I cant display both pulse and no pulse voltages.  At 16:30 there is a true ramp down of Voltage and Current as the sun loses its power similar to the ramp up at the beginning of the day. Thus we see the Two Stage controller at work Ramp and Dump unfortunately this system Dumps the best Soar Power of the day. 

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Below is a graph covering the period either side of the above day showing the shamefully shallow Solar charge. Sargent sent me this at the time they considered there was nothing abnormal.


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It can be seen here that I am a mean B****** I managed to keep the Voltage from dropping much below 12 Volts by rationing Lighting, Television and forcing Mrs Marconi to prepare and cook the evening meals in the dark. What! she had the light of the gas flame to see by.
I would like to thank Sargent and AuotSleepers for the bruising I suffered and for stealing a year of my life. The other not related to Solar problems are still not sorted so the suffering has still not ended.

EEK. So do you have any reason to think that Sargent / AS will be changing anything?

gassygassy wrote:EEK. So do you have any reason to think that Sargent / AS will be changing anything?

I wouldn't put your shirt on it, I am sure they have some misguided attempt at 'keeping both batteries topped up' in mind, they have been fiddling for years in all the ECXXX models and failed. AS need to turn to Germany for something that works instead of 1980's technology in Current consuming fancy dress.

Remember that they bought Marquis Motorhomes and you might be tempted to think they might have their eye on Sargent as well.
Anyway I am sitting in my Nuevo on my driveway pretending I am on holiday. The mains is connected so I have 13.5v on each battery. I checked the battery terminal voltage with my dvm and it corresponds within 0.1v to the reading on the AS display panel so I'm happy with that. Meanwhile I found a cup full of water left in the kettle from October when we last used it so I made a berw and am watching iPlayer.
.....must remember to turn the gas off at the manifold.....
And when Gasit returns to work I must send them a photo of my tank to ask if it is installed properly. I have seen their video on the subject and I think it is slightly ambiguous. Why does it show empty and then take 8 litres to fill?
I'll post a separate topic on what I did recently to the van. . . . .