The more I read about solar panels the less I understand. I started off thinking about a generator but now lean towards solar. What I am looking for is;
advice of the best solar system, do all systems shut down when a small portion of the panel get in the shade.
how big should my system be, we have a camper 2x100 Ah batteries to run a 65ltr fridge freezer, led lights, an inverter for a CPAP machine and the normal things like phone charging, electric water pump etc.
I read a lot about controllers which is the best to buy and can I get the panels and controller in a pack, I have watched the guy from kick ass and they seem tough and reliable or I that good marketing, www.australiandirect.com.au/kickass/portablesolar.
I use an Anderson plug to charge while travelling so usually the batteries are fully charged when I stop.
In conclusion I am thinking about 300w system that doesn't stop when a little shade comes over stainless steel cable to stop my panels from growing legs and the power to get to the batteries through the Anderson plug when not connected to the car and a watt meter. Am I on the right track
Martin_QLD wrote:advice of the best solar system, do all systems shut down when a small portion of the panel get in the shade.
Martin
Think of a solar panel as being 36 little generators in series. You need all of them added together to add up to sufficient volts to charge the battery. Shade on the cells is like draining the tank of your generator, no fuel no go. Shade on panels generally does not effect one cell, it effects a few. In addition when a cell stops charging it goes reverse polarity which further effects the output of the panel. If you put a few of those little generators out of action you don't have sufficient voltage to charge the battery. It's just a fact of life, no fuel no go.
There are a few panels around that were marketed as shade resistant. The cells in those were not the rectangular blocks. Their cells are long and thin stretching from one end of the panel to the other. The idea of those was when shade from a tree or light pole cut across the panel it would cut across all cells or the end of the panel and this only shaded part of each cell. the rest of the cell would still produce its full voltage but with less current generated. That way you did not loose the charge completely like if you shaded a few cells at the end or middle of the panel
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PeterD Nissan Navara D23 diesel auto, Spaceland pop-top Retired radio and electronics technician. NSW Central Coast.
The more I read about solar panels the less I understand. I started off thinking about a generator but now lean towards solar. What I am looking for isadvice of the best solar system, do all systems shut down when a small portion of the panel get in the shade.
how big should my system be, we have a camper 2x100 Ah batteries to run a 65ltr fridge freezer, led lights, an inverter for a CPAP machine and the normal things like phone charging, electric water pump etc.
I read a lot about controllers which is the best to buy and can I get the panels and controller in a pack, I have watched the guy from kick ass and they seem tough and reliable or I that good marketing, www.australiandirect.com.au/kickass/portablesolar.
I use an Anderson plug to charge while travelling so usually the batteries are fully charged when I stop.
In conclusion I am thinking about 300w system that doesn't stop when a little shade comes over stainless steel cable to stop my panels from growing legs and the power to get to the batteries through the Anderson plug when not connected to the car and a watt meter. Am I on the right track. Martin
Hi Martin
The shading problem can be also addressed by having several panels working in parallel. Say 3 x 100 watt panels or 4 x 80W. if they all have their diode fitted they will work individually if necessary with out problems. Better than one big one IMHO anyway ! More work setting up though.
Not sure why there would be a SS cable in the way. Drill the side rails and file a slot so the cable can go through that behind the working face. Then use a lock etc.
IMHO some marketing videos etc are well done and get a lot of people in the door Most are over priced for a marginal system. Just buy panels off ebay from a local seller at the best price delivered and wires from Jaycar or similar and a MPPT Tracer reg. Then the regulator should go permanently near the battery with a seperate anderson plug to feed it.
Thanks Jaahn and PeterD for your replies. I have been doing some reading and along with what you have written it is becoming clearer, sometimes I over think something and it becomes complicated I will stick to the KISS principle and keep it simple. Ebay sounds the way to go and from what I have read and what you have said Jaahn the MPPT controller is the way to go, Thanks again.
Martin
Martin, With the solar setup, just remember you must have have at least 150% larger solar watts than Ahr in the cells. even more is better. This gives you a greater chance of getting a full charge with some cloudy days. The regulator will keep the batteries safe.
hi Martin Qld Panels have dropped even from 2-3 yrs ago. Any of these ebay panels are ok Bitdeals , Sunyee, Vic offroad people on the forums do at least Always check sq meterage of panels some people overstate there panel sizes. Check against Kyocera ,sharp etc zat Aussie batteries and solar Assuming you are going to have some fixed on camper and some portable ?? 4x4 supa center has 160watters folding about 200$ Try and get at least 200watts on the roof Have the batteries onboard with the controller Have the connecter for the solar charger on the A frame . All panels feed to this .
hope this helps I would consider your consumption of amps above average Closer to greater than 400 watts solar would be great Assuming the fridge is 12/240v Some CPAP machines can a fair bit of power . There are only a few that are good on 12v
On a very hot day your fridge can consume at least 50AH 100AH available 50% of batt capacity beyond that damage occurs
200watt panel works out to around 48AH production in 24hour period 400 watt panel 96ah approx. production
U can only use what u can recharge
Victron Energy controllers are highly recomended
regards
-- Edited by swamp on Thursday 2nd of March 2017 11:20:36 PM
- no such thing as a cheap MPPT (a good PWM is often better value, esp in Australia)
- shading is a serious issue, so it's a good thing to try and avoid - maybe add a folding one to the mix?
- having multiple panels on the 'van means less likely that all shaded at once, so you'll get some charge
CPAP machines are more efficient on 12Volt, so if there's a 12V adaptor it'll be worth it. On 12V they draw about 15-35 Ah from the battery over 8 hours, with the humidifier off, much more with it on.
The 65 litre fridge-freezer will draw about 45Ah each day (depending where/how it's used).
If that's all that's drawing power then looks like you'll be using about 70-85Ah per day (a TV will add another 15Ah or so).
So your battery size (200Ah) is about right - any room to up it a bit?
And in Brisbane you'd need at least 400 Watts of solar to support that usage all-year round, but less if you plan to avoid winter travels.
- no such thing as a cheap MPPT (a good PWM is often better value, esp in Australia) Never a truer word spoken, unless you have around $1,000 to throw at an MPPT controller buy a good quality PWM controller such as the Plasmatronics Dingo 20/20n and spend the $$$ left over on more solar, you will be way in front.
T1 Terry
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You can lead a head to knowledge but you can't make it think. One day I'll know it all, but till then, I'll keep learning.
Any links to any sites or products is not an endorsement by me or do I gain any financial reward for such links
- no such thing as a cheap MPPT (a good PWM is often better value, esp in Australia) Never a truer word spoken, unless you have around $1,000 to throw at an MPPT controller buy a good quality PWM controller such as the Plasmatronics Dingo 20/20n and spend the $$$ left over on more solar, you will be way in front.
T1 Terry
Hi
Another exaggerated statement by Terry. You can get a good MPPT controller for a fraction of $1000 that will do your caravan. PM me if you want more information. PS I do not sell them.
However i would agree that spending any spare dollars on more solar will leave you in front.
Jaahn
-- Edited by Jaahn on Saturday 11th of March 2017 09:57:41 AM
I've had a Morningstar 30a regulator on 340w of panels since they first came out.
Never missed a beat, and battery's (with sun shining, always floating,
Also I have a small 10a "WINKONG" Regulator from Ebay.
runs panels to rear battery on Ute.
Unless you have a zillion battery's and\or panels with van loaded with electrics.
The average joe will do fine on a decent PWM unit.
Just don't try to op up too much with too little hey.
I did try a coupla cheap units off ebay originally, for carport panels.
They still in shed in box. and a Morningstar 6a does job for over 10 yrs now.
Out in open.
Be careful. Some of these cheap ones are NOT fully waterproof.
No matter what you have in Solar. STILL have a genny with 20\25\40a Smartcharger from home.
Sun no shine. solar no come to you. regardless.
I've been using solar for over 30 yrs. Genny forever. NEVER go anywhere without both. Something like a knife to a gunfight. You can't win.
Depends on the skill level of the gun fighter and the knife fighter. The gun fighter needs the advantage of distance and accuracy, a well thrown knife will beat a poor shot every time.
If you need a generator you need to seriously look at your charging system or battery storage. For the same $$ to buy, maintain and operate a generator I believe better solar, DC to DC charging and better batteries will win in the long run. There are a lot of places these days where you simply can't drag out the generator, what then? The knife fighter wins perhaps?
T1 Terry
__________________
You can lead a head to knowledge but you can't make it think. One day I'll know it all, but till then, I'll keep learning.
Any links to any sites or products is not an endorsement by me or do I gain any financial reward for such links
- no such thing as a cheap MPPT (a good PWM is often better value, esp in Australia) Never a truer word spoken, unless you have around $1,000 to throw at an MPPT controller buy a good quality PWM controller such as the Plasmatronics Dingo 20/20n and spend the $$$ left over on more solar, you will be way in front.
T1 Terry
Hi
Another exaggerated statement by Terry.You can get a good MPPT controller for a fraction of $1000 that will do your caravan. PM me if you want more information. PS I do not sell them.
However i would agree that spending any spare dollars on more solar will leave you in front.
Jaahn
-- Edited by Jaahn on Saturday 11th of March 2017 09:57:41 AM
I believe the term is an "Oxymoron" You can not put "good quality MPPT" and "a fraction of $1,000" in the one sentence unless you are twisting things by saying 99/100 is still a fraction MPPT controllers that will out perform a quality PWM controller and/or work together on the one battery at their max output are not available on the general market place for under $1,000
I happy to participate in a face to face challenge to prove me wrong, I'll be at Stone The Crows so that would be a good place to do it in front of a few hundred people. I plan to build such a set up for one of the demonstrations linked to a few talks I've been asked to deliver to prove the point one way or the other, I'm happy for anyone else to enter the challenge if they wish.
T1 Terry
__________________
You can lead a head to knowledge but you can't make it think. One day I'll know it all, but till then, I'll keep learning.
Any links to any sites or products is not an endorsement by me or do I gain any financial reward for such links
Thanks everyone and it is obvious to me from what has been said it is like the age old questionwhat is better holden or falcon. I have settled on 250w panels with an mttp controller which now brings another question, I have the two 100ah batteries in the camper and an ark pak which we use for mobile phones etc etc . So if I run the panels to an anderson plug splitter how can I control the power going to the camper and the ark pack, if I let the charge go to the ark pack through an anderson plug it doesn't go through the charger it charges direct therefore I can cook the battery. Not sure this is clear I will try it another way, I have one charge going to two battery setups, which one will the controller listen to when it comes to the batteries being full, the camper, which will then over charge the ark pak or the arc pack which will under charge the camper.
The short answer is never charge any battery without a controller in the wiring. If you charge the van batteries with a controller then you can tap off the controlled battery connections to charge the arc pack if the battery type is the same and they will get to the same controlled voltage as the van batteries.
Otherwise you will have to manually control what goes into the Arc pack and continuously monitor it with a meter so it does not cook it. Not recommended unless you know what you are doing and are in attendance also. If the two battery types are not the same then you cannot properly charge them connected together. Simple !
Back to Terry ! He has an agenda ! Perhaps it is because he is involved in a business fitting lithium batteries to caravans ! But I have no interest in a slanging match with him or others. If people wish for any information from me they can PM me and get unbiased opinions formed from 15 years of using solar for camping, and home use. I do not sell anything and believe in using tried and proven methods that work for me ! But if you want to look at a stunt by Terry to prove something at Stone The Crows, whatever that is, then go and be amazed
However it is a shame he has dominated this part of the forum with his ideas and talks down any people who disagree with his point of view. A lot of technical graphs and jargon that just turns people off asking a simple question. Pity ! I note some previous posters now do not bother anymore !
Sad that nothing changes, put up a straight forward challenge to prove who is right and who is wrong and it is put down as a stunt rather than taken up with the confidence they type with.... what can I say? I do install custom lithium battery system using what ever equipment the user already has be it MPPT or PWM. After all the lower priced MPPT controllers have fallen over only the high priced remain functional yet the Plasmatronics PWM controllers simply keen on keeping on with never a problem.
My knowledge comes from hundreds of system in all sorts of RV's and stand alone off grid systems, not just a single system I built and believe is the best bar none. Sorry if some people can't handle facts and would rather read incorrect information. I have no agenda to sell one product over another, but I won't endorse something that just doesn't do what the seller claims.
What really irks me is when a claim is made but the person is unwilling to put it to the test to prove it right or wrong but rather chooses to attack, sad but I guess that is the way on the internet forum
T1 Terry
__________________
You can lead a head to knowledge but you can't make it think. One day I'll know it all, but till then, I'll keep learning.
Any links to any sites or products is not an endorsement by me or do I gain any financial reward for such links
I've opened up eBay regulators that say MPPT all over the place, but the circuitry inside is a simple PWM (and a bad one at that). Maybe you've had similar experiences?
Best of luck with your demo - if I had money it'd be on the Dingo PWM for sure vs a genuine MPPT - especially on a sunny day! Once the extra cost of the MPPT is factored in, it's far better to go with the PWM and just increase solar with the money saved.
I've opened up eBay regulators that say MPPT all over the place, but the circuitry inside is a simple PWM (and a bad one at that). Maybe you've had similar experiences?
Best of luck with your demo - if I had money it'd be on the Dingo PWM for sure vs a genuine MPPT - especially on a sunny day! Once the extra cost of the MPPT is factored in, it's far better to go with the PWM and just increase solar with the money saved.
Cheers
AJC
I've opened up lots of them after they have died from either over heat or poor soldering on the board and some of their ideas regarding MPPT operation are quite bazar to say the least. Often users assume the 16v or so they see on the input side is the maximum power point for the panels at that temp, but more often than not it is actually the voltage the MPPT controller needs to get sufficient voltage differential to actually keep operating. A quick and dirty test is to connect the solar input direct to the controller output and measure the amps, more often than not it is higher than the output with the MPPT controller in between. Naturally this only works where the solar voltage is a rough match with the battery voltage, 32v into a 12v battery is going to have about 1/3rd the current flow so in these cases the MPPT is doing something if it is a true MPPT controller.
Once past the bulk/boost stage all solar regulators are PWM control, not all seem to understand that, the only period there is any gain to be had by the MPPT process is during the bulk/boost charging phase and that is rarely when the sun is at the best angle to produce the most from the panels. Once any controller drops into PWM mode the full capability/output from the panels is not supplied to the battery bank, otherwise the voltage would run away and wreck the battery.
T1 Terry
__________________
You can lead a head to knowledge but you can't make it think. One day I'll know it all, but till then, I'll keep learning.
Any links to any sites or products is not an endorsement by me or do I gain any financial reward for such links
hi
Martin Qld
Mppt controllers E-Tracer , Morningstar Victron energy all at a fair price . The Morningstar are the dearest , Victron in the middle price wise and the ETracer the cheapest .
Quality wise the Victron and Morningstar would be similar . The E Tracer are average but not garbage .
I get amperage boost of around 13-15% Surges if batts are near 1/2 flat to around 30% amp boost
From the Official M/stars u tube vids the Morningstars boost around 20% on average and up to 30%
Some of the reason I went to E- Tracer Mppt was cost return basis approx $$150-170 --30amp unit . I cannot fit anymore more panels either.
Beaware the size of controllers vary a lot so make sure you can fit it in . I suspect the Victrons are smaller in size .
hi Martin Qld Mppt controllers E-Tracer , Morningstar Victron energy all at a fair price . The Morningstar are the dearest , Victron in the middle price wise and the ETracer the cheapest . Quality wise the Victron and Morningstar would be similar . The E Tracer are average but not garbage . I get amperage boost of around 13-15% Surges if batts are near 1/2 flat to around 30% amp boost From the Official M/stars u tube vids the Morningstars boost around 20% on average and up to 30%
Some of the reason I went to E- Tracer Mppt was cost return basis approx $$150-170 --30amp unit . I cannot fit anymore more panels either. Beaware the size of controllers vary a lot so make sure you can fit it in . I suspect the Victrons are smaller in size .
Hi swamp
That's a good summary I think. I did buy a Tracer after some research and found it good, reasonably priced and worked as you said and put out more than the PWM regs. I have recommended them to some people and they have been happy with them. My old one is still going OK as far as I know years later.
I now have a Victron which I purchased on a good special or I would have bought another Tracer. The Victron was as cheap as the Tracers but bigger capacity at the time(for expansion). And you can buy many of either for that price Terry said was the minimum you could get a good one for !! Just deceptive BS, Donald Trump style rubbish fake news.
Another possibility with a good MPPT regulator, is to use higher voltage panels and reap the benefit of them in lower light situations. 24V panels or house panels may be cheaper to buy too. Not much power available at lower light but a trickle is better than none with a standard PWM setup. The MPPT reg will find the best output. Also using portable panels setup at an angle allows them to run much cooler than flat on the roof and output considerably more current. I will not bore people with a graph. I have several PWM regulators to compare them with.
Jaahn
-- Edited by Jaahn on Tuesday 14th of March 2017 09:38:26 PM
Consider wiring the panels in series , complete with bypass diodes, and using a MPPT controller than can take a high input panel voltage. e.g. Victron 75/15 : 100/50 or similar.
I have 4 x 12 volt panels in series, into a MPPT 100/50 charger and it is encouraging to see charging under very low light conditions. It is normal to commence harvest of power 1/2hr after sunrise and can remain in float mode providing any consumed power until 1/2hr prior to sunset. This is with the panels on the flat roof. Panels are removable and can be located remotely if required. More difficult to express the performance advantage on heavily clouded days.
A further advantage is the huge reduction in voltage drop losses. With 4 panels in series against in parallel this is voltage x4 but 1/4 the current. For example a panel circuit with 4x parallel panels at say 0.5 volt drop and a 20 amp PV charge. This equates to 10 watt loss in the cables (as heat). Having the same 4x panels wired in series decreases the current to 20/4 = 5 amps and correspondingly the volt drop to 0.5/4 = 0.125volt. The resulting loss of power due to volt drop is reduced to 5 x 0.125 = 0.625 watt. If there were only two panels in series this would equate to a 2.5 watt loss in lieu of the 10watt loss of parallel panels. Typically you would reduce cable size with series panels as a compromise to voltage drop and power losses.
Acknowledge the system PV voltage can peak above that which some may not be comfortable with.
Hi Jahhn One needs to remember that many statements claiming MPPT have no /little advantage are based on use with batteries that hold around 13+volts over their full operating range
Absolutely cannot be compared for use with LA batteries where the voltages are much lower particularly when in low SOC. Of course if the solar panels actual PPP is just slightly above the battery voltage ,a MPPT regulator has nothing to work on.
\ Some just do not like stating ALL the facts!!!
That is something that all readers should be made aware of.
-- Edited by oldtrack123 on Thursday 16th of March 2017 04:48:17 PM
Hi Jahhn One needs to remember that many statements claiming MPPT have no /little advantage are based on use with batteries that hold around 13+volts over their full operating range
Absolutely cannot be compared for use with LA batteries where the voltages are much lower particularly when in low SOC. Of course if the solar panels actual PPP is just slightly above the battery voltage ,a MPPT regulator has nothing to work on.
\ Some just do not like stating ALL the facts!!!
That is something that all readers should be made aware of.
-- Edited by oldtrack123 on Thursday 16th of March 2017 04:48:17 PM
Like lead acid batteries will not remain at the low voltage while charging but actually climb to higher than 13v?
That the PPP as you call it isn't the same as marked on the back of the panel as the test method used to produce that figure do not match real life. The percentage reduction in the "PPP" figure per *C above 25*C needs to be added to the calculation and that temp is actually around 70*C in full summer sun
That MPPT controllers like any other device are inefficient, that is why they require a heat sink to dissipate the heat generated and that heat is wasted energy that could have been used to charge the battery.
Just a few of the things the MPPT choir don't like to mention but readers should be made aware of, theory and reality rarely match ;) In theory reality and theory are the same, in reality they rarely are :lol:
T1 Terry
__________________
You can lead a head to knowledge but you can't make it think. One day I'll know it all, but till then, I'll keep learning.
Any links to any sites or products is not an endorsement by me or do I gain any financial reward for such links
Most are over priced for a marginal system. Just buy panels off ebay from a local seller at the best price delivered and wires from Jaycar or similar and a MPPT Tracer reg. Then the regulator should go permanently near the battery with a seperate anderson plug to feed it.
You can get a good MPPT controller for a fraction of $1000 that will do your caravan. PM me if you want more information. PS I do not sell them. 
If the two battery types are not the same then you cannot properly charge them connected together. Simple !
