Temporary stop to solar panels charging house batteries

LyntonB · Member

Temporary stop to solar panels charging house batteries

Mike Harding · Guru

You'll probably receive better replies by posting this again in the "General" forum and with a much more specific subject line.

I strongly suggest you ask the manufacturers or their dealers this question and I really strongly suggest that if you decide to walk on the roof you use lightweight (pine?) load shedding planks.

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I assume your panel array is "extra low voltage" ie. below 120V DC (iirc)? If so you can safely play with its connections at the controller end, just disconnect them one at a time and insulate the one then the other, providing they don't touch all will be good. You can mess with ELV systems with zero personal safety risk.

Edit: I suppose another option is that you could do it at night - seriously :)

-- Edited by Mike Harding on Saturday 7th of January 2023 01:18:47 PM

LyntonB · Member

Thanks Mike. If possible, I would like to avoid covering the panels. Yes, my panel array is ELV. I cannot disconnect the cables at the controller because the controller is behind a wall panel - only the fascia is displayed on the outside. Maybe I can disconnect the batteries safely if I insulate the terminals of the cables to the batteries to avoid them touching when disconnected. Or maybe I can remove a fuse on the positive cable coming from the controller. I have honestly thought of your suggestion of disconnecting the batteries at night, but can I leave the cables disconnected for a day or so if I insulate the positive and negative cables to prevent them from touching.
BTW. I am resorting to consultation via this forum because the company which installed my solar panels has not responded to a couple of approaches I have made. I guess they want the business of replacing the batteries!

-- Edited by LyntonB on Saturday 7th of January 2023 03:34:28 PM

Cuppa · Guru

LyntonB wrote:
I want to replace the two 100Ah AGM house batteries in my caravan. I can disconnect the CTEK charger from the batteries, but they would still be charged from 3 roof top solar panels via a 30 amp solar charge controller. I want to stop the panels from charging the batteries before I disconnect them for replacing. I have some black plastic which I will tape in place with gaffer tape. However, it seems like I will have to walk on the roof of the van to do this. My query is: can I walk on the roof of my 2009 Crusader Mk2 caravan? . Thank you for your advice, in anticipation. LyntonB

Assuming you have a 12v solar system.

Do you have some blankets you can throw over the panels, maybe using a pole or broom to push them into place if need be, to save having to walk on the roof. ie. something heavy enough to sit on the panels without being taped. I guess you would need a suitable step ladder, or be able to park somewhere next a high bank. Eg a stock loading race or the delivery area of a local supermarket. Even the back of a ute. Still good practice to wrap some insulating tape around each terminal as you remove them though.

LyntonB · Member

Thanks Cuppa. I think in the end I shall do something like this. Thanks again. Your and Mike's input highly valued!

Jaahn · Guru

Would it be too obvious to say do the job at night when the panels will not be generating power. !

Jaahn

Radar · Guru

LyntonB wrote:
Thanks Mike. If possible, I would like to avoid covering the panels. Yes, my panel array is ELV. I cannot disconnect the cables at the controller because the controller is behind a wall panel - only the fascia is displayed on the outside. Maybe I can disconnect the batteries safely if I insulate the terminals of the cables to the batteries to avoid them touching when disconnected. Or maybe I can remove a fuse on the positive cable coming from the controller. I have honestly thought of your suggestion of disconnecting the batteries at night, but can I leave the cables disconnected for a day or so if I insulate the positive and negative cables to prevent them from touching.
BTW. I am resorting to consultation via this forum because the company which installed my solar panels has not responded to a couple of approaches I have made. I guess they want the business of replacing the batteries!

So this means when you need to replace the solar controller you throw the caravan away and buy another.

Surely you can get to the wires some how, what happens if you need to reset the controller, my laymans experience you disconnect the wires from the controller and reconnect the wires to do anything with your 12 volt dc electrical.

With our Voltech regulator, to disconnect, remove the earth wire to the battery first, replace last.

Have a good look at that panel.

Hylife · Guru

If you have an industry standard solar controller, the connectionsare:- left two are solar, middle two are battery, right two are load control.
Just remove the positive on the solar connection first then feel free to go ahead and disconnect power to your battery charger and then remove the batteries last.

Always batteries are the first connection and the last disconnection.

LyntonB · Member

Thank you very much Hylife. My controller has only two connections: solar and battery. I guess your procedure still applies. Thanks again.

BAZZA44 · Senior Member

All I do to isolate my panels is get a step ladder to reach the roof of van and then throw some old curtains over the panels. If wind is too strong I place some light timber carefully over the curtains.

Barry

Aus-Kiwi · Guru

Early in the morning or late in evening? I have 3 way splitters no problem isolating. Its not like theres stored electricity like a battery !

LyntonB · Member

Thank you all for your advice. All were carefully considered.

In the end, I covered the roof of my van - and therefore the solar panels - with a canvas tarp over which I pulled a plastic tarp. A check of the controller showed that no power was being produced by the solar panels. Then I was able to disconnect the two house batteries and tape the four lots of cables with gaffer tape to avoid any contacts. The old batteries are now in my garage awaiting disposal.

Again thank you all for your input. I appreciated them all very much.

Stretch60 · Senior Member

Whilst you are at replacing the batteries, fit a solar disconnect between the panels and the controller. So much easier when working on your system.

-- Edited by Stretch60 on Tuesday 4th of July 2023 09:23:34 PM

Are We Lost · Guru

The original post was 6 months ago, but tips are always useful. I agree with Stretch about isolation switches - I have a switch for turning off the regulator too.

My tips, are:

there is no need to be pedantic about fully covering the panels. It does not take much shade on each panel to reduce the output to very low levels
when reconnecting the system always connect the regulator to the battery first, then connect the solar. This is to avoid damaging the regulator. Some may not be an issue but a sudden spike from connecting that solar while it is disconnected from the battery is a risk. When disconnecting I do solar first, then battery, although there is less risk with that.

Aus-Kiwi · Guru

I just removed the terminals . Earth first . Then put a leather glove over the active / positive. Being a lineworker its second nature to me . Turned everything off inside . Disconnected solar cables first .

woolman · Guru

There should be a switch before the controller to turn off solar charging.

Neil

Dick0 · Guru

woolman wrote:
There should be a switch before the controller to turn off solar charging.
Neil

Yep, that's where the Solar Isolator switch should be. That is much better than throwing blankets over solar panels!

Burt65 · Member

Dick0 wrote:
woolman wrote:
There should be a switch before the controller to turn off solar charging.
Neil
Yep, that's where the Solar Isolator switch should be. That is much better than throwing blankets over solar panels!

It is also the law. There should be an isolation switch for every connection..

BarneyBDB · Senior Member

What Law ???

TimTim · Guru

x2?

Peter_n_Margaret · Senior Member

Overload and short circuit protection of PV wiring is required as per the new version of "AS/NZS 3001.2 Electrical Installations", but is not retrospective.
Typically that is achieved using a circuit breaker.
Cheers,
Peter

TimTim · Guru

Yes for residential and commercial installations but we are talking about ELV PV systems in caravans and mobile homes.

As I have shown in numerous links before, Australian Standards are not laws but they may be referenced in legislation.

So how about providing the link to the Act and Regulations that you are referencing for caravans and mobile homes. Provide the link to the Authority that controls the said Act and Regulations that you say that exist, and provide a link to the penalties that apply.

An isolation switch for the PV was not provided in my caravan when purchased nor in a friends caravan that was recently purchased so I would be interested in which laws were broken by the manufacturers

I installed two additional solar panels yesterday without an isolation switch, so again I would like to know which laws I have 'supposedly' broken.

Have a nice day biggrin

Peter_n_Margaret · Senior Member

Tim, AS/NZS 3001.2 applies to "Transportable buildings" which includes any caravan or motorhome that can be connected to the 240V supply network.
I know that you beat this drum about Standards not being law, but if you, like most discerning buyers, refuse to purchase a caravan or motorhome without an electrical certificate, then your constant protestations about this are toothless because you won't get one unless it complies. Legislated, or not.
You can do as you please, as will others.
In the meantime, AS3001.2 requires circuit breakers on new PV installations on 99% of caravans and motorhomes.
Cheers,
Peter

TimTim · Guru

Burt65 stated that an isolation switch was required by law then Barnaby Bob and myself questioned what law. Then you posted a reference to AS/NZ 3001.2 without posting a link to the legislation that calls up that Standard. Yet you know very well that VBS1 (Version 6) which is written under the Commonwealth Australian Design Rules and was amended in August last year, still calls up AS/NZ 3001:2008. There are no requirements for PV systems in that Standard.

'7.3 Other electrical systems
Electrical installations on a trailer that are intended for connection to an AC power system other than that of the tow
vehicle must comply with Australian Standard AS/NZS 3001:2008 Electrical installations Transportable structures and
vehicles including their site supplies.'

I go on about Australian Standards not being law because the simple fact they are not. They are documents that may be in part or wholly referenced by legislation. Again straight from the Standard Australia web page.

'Standards and the Law

On their own, standards are voluntary. There is no requirement for the public to comply with standards. However, State and Commonwealth governments often refer to Australian Standards® (AS) or joint Australian/New Zealand Standards (AS/NZS) in their legislation.

When this happens, these standards can become mandatory.'

So now that you can't back up your 'law' post with the relevant link to legislation you now start the scaremongering about not getting an electrical certificates when in fact I have one and my friend has one as well. And before you say they aren't worth the paper they are written on, they are because they refer to the appropriate Australian Standards.

At the end of the day it up to each individual what they do, whether it be adding more solar panels or installing LifePO4 batteries, but when people says something is law then at least post the link to support their claim.

Have a nice day smile