Hi there! I dont understand anything of energy, let alone solar energy.  I got a guy to install it on my van and it is not working.  If somebody can give me some advice/clarification/etc, I will be very grateful.

This is my equipment and what I would like very much to use it for:

1 DC-12V-140AHX  Giant Power 140AH 12V AGM Deep Cycle Battery
(this battery is also connected to the car's battery)

MPPT Solar charge controller  20A

Renoster 3000W/6000W Pure Sine Wave Inverter Power Converter DC 12V to AC 240V with Rechargeable Remote Control LCD Display 2 AC Outlets and 2.1A USB Port for RV Truck Road Travel Emergency Tools

3xAcemor 12V 300W Solar Panel + 20A Controller 2 USB Charge Power Caravan Camping Battery

The panels were installed in parallel.

Geko 47L Fridge

1 lap top

1 battery for wifi mobile modem

1 battery for phone external battery

1 phone

1 Water pump (only turn on when using water - very rarely for about half a minute as the water tanks are leaking - it seams they are not connect between themselves.

2xLed lamp

I am not using the electric stove, and I dont have energy for anything.

I was told to buy one 105A MPPT Solar charge controller.  I have 4 Solar charge controller  20A (3 came with the panels and I was told to buy one separately)  but I was told they cannot be connected.  I was also told that the solar panel cannot be in series because I would have only 300W instead of the 900W parallel (cannot understand this).

I understand a little of mechanic, but I am a big zero in electricity.  I thank you very much for any clarification you can give me.

Wish a happy sunny Sunday to everyone.

Let's start with the Acemor 300 watt panel

1.300m x 0.998m = 1.297 square metres

300 watts ÷ 1.297 = 231 watts per square metre

I would suggest an upper limit of 170 watts per square metre.

1.297 x 170 watts per square metre = 220 watts

Or

1.297 x 150 watts per square metre = 195 watts

I think 195 watts is more realistic, but I'm more than happy to be proven wrong.

Why provide a 20amp (output) controller with a 300 watt panel? Because the panel will not provide 300 watts.

I can get up to 11.3 amps out of 120 watts. That would work out to 28.2 amps if I had 300 watts. But my panels & controller are top end hardware. Just the 20 amp controller alone is about $200.00 then the panels on too of that.

Another issue is plastic corners of solar panels, avoid them like the plague.

I will be blunt! You should return your panels.

The controller which came with each panel can go in the bin.

You can't have a quality 300 watt panel & quality MPPT for $149.00

Now it gets even sillier!

2 x 300 watt panels packaged size 1.080 x 0.710 = 0.767 square metres.

300 watts ÷ 0.767 = 391 watts per square metre!

I have done some back of the envelope figures for you. I will leave it to others to add their comments!

Eremita wrote:

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PS: I also dont know how to post here. I hope I am posting at the right place.

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 Hi Eremita 

Hmm third try lucky I guess. Possibly you could say on the other posts to come to this one as it might stop having three threads going in three areas. 

Now to business. You have a collection of items bought on the cheap by the looks of them. The battery is the same as mine so should be OK.

One of those solar panels with the simple PWM regulator should surely work OK if connected up to the battery. If not why ?? Did your installer know anything. Is the wiring actually connected for them, in parallel, as you said or not.

Another person has suggested they are not up to specs as they are not big enough. Possibly true but you have three of them and they might be enough power anyway for the battery. It might be OK but not perfect like he might like to have. Do not throw the regs in the bin just yet. But I would be interested in the brand and type of the MPPT regulator as there are fakes out there cheap. 

We must try and get this lot sorted out as it is mostly untrue ! "I was told to buy one 105A MPPT Solar charge controller.  I have 4 Solar charge controller  20A (3 came with the panels and I was told to buy one separately)  but I was told they cannot be connected.  I was also told that the solar panel cannot be in series because I would have only 300W instead of the 900W parallel (cannot understand this)."

There are conflicting ideas on multiple regulators but mostly they are not correct and it is possible to run them into the same battery. But lets not rush into any decisions now before deciding on some basic plan to get it all working or changed or whatever !

Lets have a sensible discussion on the facts you supply !Are you in lockdown in the Sydney area currently ?

Jaahn

Thank you!

Are the solar panels on ABS mounting pads (& not the pretend fake non ABS ones). They should be bonded down with Sikaflex acrylic & not silicone. Also additional side pads for large panels.

https://www.jaycar.com.au/white-abs-solar-panel-corner-mounting-brackets-set-of-4/p/HS8860

https://www.jaycar.com.au/white-abs-solar-panel-spoiler-mounting-brackets-pair/p/HS8864

Maybe provide a few photos, so some suggestions to help fix the leaks.

Eremita wrote:

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Hi everyone! First of all, thank you for your response. Appreciate very much.
Jaahn, yes, we are in lockdown until Friday 9/7. It might change. Who knows? I am trying to learn as much as I can about this so when we are "unlocked" I will be able to do something about it. The thing is I am getting more and more confused. There are so many choices and I cannot start from scratch now. I will have to do the best I can with what I have.
The panels are already attached to the roof (the rain is leaking through the screws). I have some sealant that I bought specially, but I cant climb up there. The ladder is not high enough. I am shorty. And it is raining koalas and wombats around here.

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Hi Eremita 

Well it seems to me you have some of the hardware to make things work. So we have to see if you can find out why it is not working yet. Your panels and the regulators should generate power and charge the battery. Each of the three panels and a regulator each should work and can work together  and should generate enough power to get on the road most likely. 

What you should try to find is a person who has some basic electrical knowledge and is very handy and able to check it out. A person who knows a bit about cars and wires and how to connect them. Not rocket science if you stick to the 12V stuff. Difficult under lockdown. 

The same applies to the screws and the leaks. Not hard to fix but you need a person that does know what to do and what sealant to use. Possibly the holes were drilled in a low part and should not be even there ?? It is often better to glue them on the roof to prevent leaks ! Not rocket science either.

I will send you a Private Message later. Possibly you do not know about them yet. Just a way to send messages not on the open forum area. If you look up the top right hand corner after you log on, you will see your name in a box there. If you received a PM it will say that under there and you can click on that to read it. You can easily use the reply box to reply. 

Cheers Jaahn

Ypu can't just go screwing solar panels to the roof. Putting leaks aside. The problem is surface area. Even if you use a few screws for each corner of the solar panel. They simply do not have enough surface area. They are simply hanging on by a thread.

Every time the vehicle goes over a bump there will be a lot of stress on the vehicle. It will end up cracking the body panel. 

Screws will pull out & panels will fly off, hopefully not killing someone in the process, or into a following car's windscreen.

Every screw hole will become a stress fracture point & rust will set in & be an absolute nightmare to fix.

If you do not want to bond the panels to the roof. You need to bolt them to a roof rack or roof platform which in turn is bolted or clamped to the correct spots on the vehicle so you do not get stress cracking of the bodywork.

This is a poorly designed roof rack rail & stress cracking can be seen around the bolt hole.

To remedy this problem I made a long section of 5083 structural aluminium to bolt into & spread the load. Additionally I have added a plate holding the rail section & leg together. So all up 12 bolts are tapped into the 5083 section or bolted through as many places as possible to spread loads.

This is why you bond panels onto the roof to spread the load as much as possible.

& a reminder when bonding the fitting to the roof it takes about 25 days for the Sikaflex to cure. It cures with air, but it takes about 1 day per 1mm width of pad.

So in other words. If the pad is 50mm wide, it will cure from both sides. So 25mm from one side & 25mm from the other side. So 25 days in total.

Hi!  Thank you very much for your help (and you are very knowledgeable!), but I cannot return the solar panels as they are already screwed on the roof.  They are not too heavy and I have room to install one more (although I had plans to put a sky light on that space later on). Another thing I dont know is if we can mix and match types of panels: power, brand, mono, poly, etc. 

Most certainly I will have to change the controller that came with the panels for the King one that seems a little more reliable. 

Another thing that is worrying me is that when I turn the van on to charge the battery, the van battery starts making a clicking noise. I get worried and I turn it off!

Have a nice day!

I will make the photos.  Have to find a higher ladder.  Today is sunnier, good day for photos.

Eremita wrote:

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the solar panels as they are already screwed on the roof.  They are not too heavy

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 A solar panel does not have to be heavy but the micro movement caused by road irregularities accumulates & causes stress cracking. You simply cannot just screw things to the roof.

You can mix & match panels. Look at the specifications on the back of it & get something the same.

Having said that before you purchase another panel you really need to benchmark your current panels. Until you know their output. Otherwise you will be throwing good money after bad.

I have looked at the King's MPPT specs. I am more than happy to be proven wrong but my person view is that I don't think it is an MPPT. Since you have bought one you could check the voltage & amp output every 5 minutes over say 4 hours. This is a bit tedious, I have done these things for days on end, but it is the only way to know what you are dealing with.

As far as the engine clicking. You need to get someone who actually knows what they are doing or this is going to end in an expensive mess both for the solar setup & vehicle.

I will be extremely blunt here. It is the blind leading the blind. I am sorry if I have offended but if you do not get the basics sorted out it will end in a very expensive long term mess.

I'll eat a broom if they are over 130!

I'm currently in the process of upgrading my solar and need a couple of panels around 100W/120W. After extensive searching on-line and doing panel area calculations I decided I could not trust most of the suppliers! Quite a few, it appears to me, simply lie about the capability of their panels.

I have decided to buy a couple of 115W Victron panels because I feel confident a company with a quality reputation will not intentionally lie, they may "massage" the truth :) but I suspect I will get, more or less, what I pay for.

Incidentally: as best I can tell solar blankets are appallingly overrated for output power.   

You have hit the nail on the head. Quality is cheaper in the long run.

I would have bought Victron panels. By the time you amortize a product over 10 years there is barely any difference in price.

I needed a size oanel that would fit a space. I bought Projecta 20 watt panels. They are very conservative in their watts per square metre rating at 113w/m² at their rated output for the overall panel size, but they have performed over specification easily. Together with very heavy wiring & a Victron controller I easily get 9.8amps into the battery with up to 11.3amps out of 120 watts of panels.

Why put on a 2 x 300watt no name brand that can't light a fart.

The most important thing is peace of mind when you are in the remote outback & you know your system will work & you always have cold beers!

Personally if I was on a tight budget, is go for quality & build up the system.

One top quality controller allowing for future solar input. A good quality panel from a well known manufacturer that you can buy additional panels easily.

Years ago I bought old welding cable to make jumper leads from a scrap metal merchant. $20 for 12 metres. Still using the cable today. They look dodgy but they work!

With a bit of planning & long term budgeting you will have the best system.

This recent article says a lot.

Either old fashioned batteries or second hand battery system worked brilliantly. Well thought out setups rather than simply buying something of the shelf.

https://www.abc.net.au/news/2021-07-03/battery-power-dandenong-ranges-tesla-agm-grid/100264988