Solar panels

@ Roopert

Yes, I’m going to do an experiment

I’m not on ehu after we leave here Friday for a week - so being on battery overnights should be enough to see what happens with solar during the following static days etc....

Not withstanding if we move the alternator will take over....

Looking forward to finding out if my solar amps changes and if I get the solar available indicator on the control panel... would love to see the solar kick in so I can eat my hat....

caraman
a lot what you have said is not wired how you are saying it is .other people have said when they have turned the vehicle isolator off have got a call for low battery voltage for the tracker .I have removed my leads on my leisure battery when I fitted a second battery and had no call .  
  the main point here is the solar is best to default to the vehicle battery when you turn the sargent system off and was wired like this before on older vans before English vans started using sargent .
as for auto-sleeper manuals are not great and have not been keeping up with the changes in the electrics. one very poor point auto-sleepers should have been ordering the vehicles with the 180 min camper radio spec not the van spec

these 'solar' threads do rumble on, with owners not really sure as to what system defaults to where, whether things should be switxhed on or off and what the effect of either might have, etc, etc...

many contributors to this forum have solar systems that are totally stand alone from any sargent PSU, have dual charging regulators that keep all batteries maintained in pretty much any weather with as little as a 100w panel...

my van has this type of system, simple and efficient and not a Sargent PSU in sight...

there is a guy next to us on site at the moment with a Hymer and, despite having a solar input point on his Shaudt Elektroblok (PSU) the dealer didnt route the solar that way....he set it up as standalone, for the same reason as has been identified with the latest resource hungry Sargent boxes....they take too much power away from the solar stream....

knowing this, why would the first course of action not be to unplug the solar system from the Sargent PSU, route it into a simple dual charge regulator and then let it get on with its job unhindered...

who cares about control panel readouts, especially if all they tell ypu is that ypur batteries are flat....arent fully charged batteries more important?

bolero boy wrote:why would the first course of action not be to unplug the solar system from the Sargent PSU, route it into a simple dual charge regulator and then let it get on with its job unhindered...

We have covered this and it's exactly what a few of us have done. I did it before Christmas and the system is now ticking along in storage with no need for any intervention now.

In terms of your comment a out who cares about displays etc, the Sargent system is actually a alot more than that and a good idea in theory.

When on hook up it sends charge to one battery while the full solar charge is sent to the other, and keeps rotating this so both batteries are being optimised. It's a shame the system can't charge both batteries when shutdown though, it's this missing aspect that causes the problem.

AFAIK, when on EHU, maintaining all batteries isnt an issue...

is clever 'optimisation' (of additional solar power) any real advantage when on EHU as theres incoming power to spare?....surely the Sargent PSU doesnt need to 'optimise' much with any solar input...

the issue for most seems to be when away from EHU and just requiring the SP to maintain all batteries while the van is not in use...IE Sargent unit OFF.

this is when the 'optimisation' (involvement of the Sargent unit) actually hinders use rather than enhances it, as leaving the unit ON (a requirement for 'optimisation') creates more drain than solar input.

to that end, surely the advantage of good off grid charging is what folk (who have no winter time ehu access) require, over some clever electronics when on ehu?

as it happens, some systems are able to do both.

when on ehu, it makes no difference whether we had a SP or not, both batteries will be maintained by the split charging process.

isnt that sufficient given that the reverse is true and that our SP does exactly the same when no ehu is present?
both these processes are managed without checking with, or being affected by, the other.... 

perhaps the Sargent system should be able to leave the internal solar regulator 'active' when the PSU is powered down...?..

then you have 'in theory' the best of both worlds...ie what i described above.

That’s excellent info, many thanks for sharing

yes it is excellent info, but it is really telling you what the issues of having a van in storage are with regard to battery drain.
whilst Sargent and AS get their story straight about turning this and that off, they admit that the 'problem' is any fitted alarm.
i have an alarm, i have a 100w panel connected to all batteries by simple dual charge low tech (PMW) solar regulator...
this is more than sufficient to maintain all batteries all year round, with the van on the drive, sometimes for a few weeks (but, in fairness not that long very often as we use it regularly)...
i have my control panel (and 12v systems) on at all times and when i enter the van (often two or three times a week, checking stuff, loading/unloading kit etc) i just look at the regulator to ensure both battery lights are flashing for 'full' (they always are) and press the 'battery readout' buttons on the control panel to 'double check' and verify the levels as i want to know if they are slipping down (they never do), even in winter, so there is sufficient charge if it isnt being sucked away by other electronics.
the solar regulator carries out its split charge duties all the time, apart from pulling the fuse there is no power down procedure, so with the regulator being inside the Sargent PSU, why isnt it possible to have a split charge system with the PSU in shutdown?
because the sargent PSU applies a 'more complex' charging algorithm than a 'simple' regulator can do...
however, the simple regulator can keep both batteries fully charged which is more than the 'complex' PSU can do.
IMHO, it is NOT essential to route solar charging via ANY complex PSU (for any brand of MH)...there is such a port on my own van but the installations on both our  Carthagos bypassed this despite being set up by a main dealer.
no doubt a fully 'factory fitted' system (from Carthago, Hymer, AS, Swift or who ever) would go via 'their' PSU...
would it be a 'better' system....?
in some cases, not.

I totally agree Chris, I have had three different motorhomes with solar panels and the cheap Chinese £20 regulator that feeds both leisure and engine batteries. As you say even in cloudy months on end a 100W panel will keep both batteries fully charged. Peering into my Sargent cooling vents with a torch I can see the same cheap Chinese £20 twin battery charger inside there but I have no idea how it is wired up, I haven't taken it to bits yet to investigate.
For reasons I won't go into, on my current 2015 Nuevo I had an extra 100W panel added in series with the standard 30W one, together with an expensive lah-de-dah regulator and two expensive Duracell batteries. This was done by a reputable caravan / motorhome workshop. I don't know what they did to the wiring other than they wired the two panels in series. I think they bypassed the Sargent and the result now is that I have full charge on the leisure batteries but the engine battery voltage is reducing as the weeks go by. I'll have to get it sorted, I am confident in electronics so I'm sure I can. I might just run the 30W panel to the engine battery using an old Chinese regulator and leave the 100W panel charging the leisure batteries, or I might just remove the lah-de-dah expensive one-battery regulator and reinstate the cheap Chinese two battery regulator.

many of the more expensive MPPT regulators are only single channel, usually charging the leisure batteries and relying on a Battery Master or similar to pass charge to the cab battery.
it may be that this is how they have set it up (without a battery madter?) and youre only getting charge (albeit now 130w worth) to the leisure side.
are you seeing any raised voltage at all at the cab battey to indicate any voltage (from either panel) is getting there?

I think bolero boy has it right

Going back 16 years I fitted 60W solar panel and PWM controller direct to my leisure battery. When we changed vans the dealer swapped it across to the new van. I would have liked a bigger panel but that was the deal. Until last year that set up served us well without any hook up use.

Since the Nuevo, our summer 2019 use was curtailed so we didn't  get a chance to test any proper solar use but I began to think that the 80W fitted panel could not be as inefficient as it seemed.
The real test has come with winter use outside the UK, a few cloudy wet days saw us running to mummy, well a site with hook up, I exceeded the total  number of days on hook up in 16 years on that site in a week.

I think the problem lies with. 1) Long thin cabling from the solar panel. 2) PWM controller. Although my previous controller was PWM and bolero boy has a cheap PWM controller, I have proved the greater efficiency of MPPT. 3) Losses in the Sargent smart charging control switching. 4) The resultant inadequate charging profile. 5) Long thin cables to the Leisure battery.

I don't want to do modifications whilst under Warranty so I have engineered a stand alone 100W panel, it can be angled in azimuth and elevation to the sun which improves efficiency but I think it would be a vast improvement on the roof also. This correctly engineered direct to battery set up brings the level to Float before midday, the AS set up has never acheived a full charge.

To be fair bolero boy says he is talking of fairly short periods of winter non use.

The 80W panel Nuevo system problem is that it doesn't even come up to a 60W panel performance, which brings me to the point I forgot. 6) The Nevo can select charging for Leisure or Vehicle battery. The charge profile cannot be right for both the performance fits an AGM battery best, a Sealed Lead Acid charge profile would damage the AGM Vehicle battery.

In practice the terminal Voltage goes no higher than 12.9V then the PWM starts a very short duty cycle of 13.5V pulses, shortly after that it will stop charging completely despite full sun at the peak charging period of the day. Hence neither battery will reach full charge, particularly the Leisure.

just to add a few bits of extra info...
1. i dont have an AS nor a Sargent PSU. all my 'electrics' are CBE.
2. although the van is on the drive for 'shortish' periods, this could be several weeks.
3. i am currently in Spain and, whilst on a hook up site, i have the charger switched off so all lights, water pump, heating fan (not really being used now), SOG fan, TV are coming from the leisure batteries charged from my 100w panel, batteries usually full by mid/late morning, although, some nights, the usage doesnt even take the batteries below 'full' so i dont see anything other than a full battery.....in fact, the only issue i had was when i left the outside awning light on all day, not realising it was on, its the only non LED light on the van, being several non LED lights....and it seemed to be a drag on the battery. this sort of battery drain might take a good chunk of solar to restore it
4. the comment regarding different battery types is a good one. leisure batteries can be gel, wet, AGM whilst starter batteries are generally wet...so getting a mains charger, solar controller or, indeed, an alternator to supply the revevant (potentially) different charging profiles to all batteries is a tricky one. i have 2x92ah Banner Running Bull AGMs (transferred from my previous van) and took advice from AandN regarding the setting on my mains charger...Gel or Wet...they said Gel so thats what its been on...the simple solar controller has no such setting and os probably not good for the AGMs which are 5 yrs old and probably due for replacement...was considering gel but the Varta EFB look good value and performance and would cure any 'battery type' issues as all wpuld be 'wet' ish....
5. we use THS sites in the UK summer and have been managing to charge electric bike batteries via an inverter, although this will take a large chunk from any leisure batteries and has to be managed. 

an interesting thread with some good thoughts and resulting options being considered.

I was surprised when the specialist garage told me my original fitted solar panel was 30Watts (2015 Nuevo). I had thought it was 80W which wouldn't be so bad. My previous experience of 100 Watt panels on 4 different vans is that 100W is fine, with a cheap Chinese regulator. However none of those vans had 'intelligent' alternators and regenerative braking.
I totally agree with the desirability of switches which go click when one piece of metal joins another piece of metal. But they are, at about 0.8p each, more expensive than writing a bit of software into a £1.30 microprocesor by the time you have made 1000 units. Years ago I was manufacturing reversing sensors when they were a novelty. Buying LEDs 1000 at a time from the manufacturer cost 0.8p each instead of 35p from Maplin

I've not had my hands on an EC700 yet so would be interested to hear how that is configured?


I have only seen the Solar controller in the Nuevo with a camera peering through a total jumble of wires in the box under the OS bunk.
It is a separate unit, how its connected is not visible. As the output is switchable smartly and by the CP of the EC700 it must be plugged in to it. It would seem to be a single output unit or only one output used.

In reply also to the comments elsewhere re real switches and relays, the EC700 uses solid state switching hence conserving power. However there will be losses in the switches which may contribute to some of the inefficiencies in the Solar Charging. Solar chargers should have no loss between their outputs and the battery.

Marconi
if you go on sargent site solar reduced you will see the lovely solar pwr regulator 15220
I have removed this and fitted a epever mppt in its place now gettint for every amp going into the mppt controller 1.4 amp out