Solar Panels

Ondway2grey · Veteran Member

Solar Panels

Dougwe · Chief one feather

G'day Mick,

If you pop this question into 'Solar Power' sub section of Techies, you will get those that know helping you better than here. That's why Webmaster has set up the GN Forum the way it is.

Keep Safe out there.

Ondway2grey · Veteran Member

Is it possible to move this from general to the techies section? Thanks.

Dougwe · Chief one feather

Just send a PM (personal message) to webmaster asking to gave it moved.

Click on 'webmaster' to open then click on send message. Just look around for 'webmaster' in any threads and click.

Edit....You could also start a thread in the Solar section then ask webmaster to delete this one.

-- Edited by Dougwe on Saturday 6th of April 2024 03:49:07 PM

Ondway2grey · Veteran Member

Cheers, PM sent to the WEBMASTER.

Peter_n_Margaret · Senior Member

What voltage are the panels?
The solar controller may need 5V in excess of the actual battery voltage to start charging. Read the specs of the controller. Which controller do you intend to use?
Here is an example... https://www.solar4rvs.com.au/assets/brochures/VIC-SCC110020160R.pdf

Cheers,

Peter

Dick0 · Guru

Hi Mick,

1. My 4 x 250W panels are in parallel array and MPPT controller charges 3 x 135AH Lithium batteries.

2. Can't help with 48V system. My setup is a 12V system and supplies 240V through a 3000W/6000W inverter as required.

What is it that you want to achieve?

Jaahn · Guru

Ondway2grey wrote:
Hi All,
Throwing a couple questions out there regarding solar.
1. Majority of the time do you wire your panels in series or parallel or series & parallel?
2. Anyone using residential solar panels to charge a 48V battery If so what Voc are you using? (I am assuming < 120V DC)
eers

Well you can use any combination of series and parallel that suits to get the voltage needed to charge the battery well, 48V in your case will mean something well in excess of 56 ++. But if you use a MPPT regulator it is advantageous to have more voltage over that requirement as the extra power in the higher voltage will be converted to extra current. If you use a PWM regulator any extra voltage is wasted most times.

It is OK to use house panels and often a good idea and they are available second hand at a great price. Buy wisely ! They can be series and parallel combinations also. The max voltage may be dictated by the limit recommended by the regulator.

Series panels can have the output reduced seriously by what looks to be minor shading of one panel in a series string. Parallel panels will often work better with partial shading of panels. There are recommendations for diodes to help with the various combinations of panel connection. Google is your friend. https://www.electronics-lab.com/wp-content/uploads/2021/06/solar-array.png

Good luck or possibly ask specific question about your proposal.

Jaahn

Bypass Diodes in Solar Panels - Electronics-Lab.com

-- Edited by Jaahn on Wednesday 10th of April 2024 09:35:52 PM

Ondway2grey · Veteran Member

Thanks everyone for the replies

I have decided to go with a 24V setup due to the charge voltage requirement for 48V (65V Voc). This meets the MPPT requirements & <120V standard.

Out of curiosity is anyone using panel fuses & DC isolator on your setup?

Ondway2grey · Veteran Member

Something of interest

Not sure when they will be available in the Aus market. Ticks the boxes for power & weight saving in a caravan.

450W rigid solar panel 8.8kg with frame for mounting.

www.pv-magazine-australia.com/2024/03/07/smart-energy-expo-8-8kg-glass-free-module-launched-by-chinas-aiko/

As per residential panels
12 year product warranty
25 year solar output guarantee.

Jaahn · Guru

Ondaway that is interesting. I always thought the heavy glass would be replaced with plastic but who knows how long it will last in the direct Aussie sun on a roof ?? Another comment would be that very big area panels possibly might not be well suited to use on a vehicle and rough roads.

My thoughts about all the new ideas on panels is that we know if you currently buy quality panels they work well and are likely to continue to do so. This is important on a vehicle as the conditions are more difficult than on a fixed house roof and problems might be more common. Why reinvent the wheel just fit and forget the existing technology. Worry about more important things IMHO.

A 24V setup seems to me to be a good compromise rather than higher voltages. There are plenty of available devices for use at this voltage as it is used on trucks etc.
Cheers jaahn

Peter_n_Margaret · Senior Member

mullerenergy.com.au/product/sunman-520w-flexible-solar-panel/
This is a 520W flexible panel from a quality manufacturer with a 5 year warranty if fitted to vehicles.
I will be fitting 420W flexible panels from this manufacturer on our new build OKA. They are 42Vmp and weigh 7.3kg.
www.solar4rvs.com.au/sunman-earc-430w-flexible-solar-panel-slim-version
Panels will continue to get better and cheaper.
Cheers,
Peter

Ondway2grey · Veteran Member

@ Peter
I also considered these. I think for your setup these are an awesome bit of kit. I intend to have the panels moveable so prefer the rigid frame.
It is always a compromise of weight, mounting options (air gap), quality, price per watt, etc.
Not sure when the Aiko air series will be available in Aus. The next best I found were REC Alpha / Sunpower Maxeon 3.

@Jaahn
Yep the 24V fit the bill for lower voltage yet met the requirements to supply an inverter while meeting the battery's continuous discharge ratings.
I have previously used domestic panels with a camper trailer using foam & over centre latches (worked well with no issues). They are also rated for hail & have a strong enough aluminium frame. I agree with your points. This is the reason I am not a fan of expensive folding panels.

This company seems to be progressing the caravan industry.

www.youtube.com/watch

Peter_n_Margaret · Senior Member

Ondway2grey wrote:
I intend to have the panels moveable so prefer the rigid frame.

I will be having a hinged one over the rear window, like the existing vehicle.

It will be mounted with ventilation on a sheet of multi wall polycarbonate roof sheeting which is under 2kg/m2.

Cheers,

Peter