Change-over switch for solar-panels to Starter and House batteries?

PaulRainbow said:
Guess you didn't actually read Daves thread about the dual controller then. You also seemed to miss my post ;



You still need to fiddle with 1-2-B switches and still have no way of charging both batteries via the alternator at the same time.
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Well if I did, then I either didn't take it in, or I've forgotten it
Ooops.

So, in plain language please, IF I now fit the PhotonicU controller, what happens when I'm running the engine/alternator using the "1 or 2 or both" position(s) on the changeover switch and have my two solar panels connected to the PhotonicUniverse controller?
 
Robert Wilson said:
Well if I did, then I either didn't take it in, or I've forgotten it
Ooops.

So, in plain language please, IF I now fit the PhotonicU controller, what happens when I'm running the engine/alternator using the "1 or 2 or both" position(s) on the changeover switch and have my two solar panels connected to the PhotonicUniverse controller?
Click to expand...

I covered this repeatedly in Daves thread.

The dual controller will charge both batteries by solar, nothing else. You should not use the Both setting with the dual controller, i don't know what will happen to the controller if you do, i suspect it won't burst in to flames, but who knows. You shouldn't be using the Both setting anyway, except in an emergency.

For less money you could bu a Victron Cyrix-1 120a VSR. It is a simple thing to fit, less work than the switching arrangement you opened this thread with. It will do what you want with your solar charging, and more. From one of my posts in Daves thread ;

key point/s..... the VSR will allow all batteries to be charged by the solar controller and the alternator. So no need to fiddle with the switch, all batteries will get charged whether the switch is on 1, 2 or Both. Please ignore anyone that says it's OK to leave the switch on "both", other than for an emergency start. It is not OK, certain conditions or battery failures can leave you with all of the batteries flat.

So, with the VSR fitted there are two very simple options for using the lovely 1-2-B switch :

1) Turn to 1, start engine, turn to 2. No need to wait on 1 for the engine battery to charge, it gets charged on 1,2, or B :encouragement:

2) Designate 1 as emergency engine start, but never use it. You select 2 and leave it there. Engine starting and all domestic function work from the "domestic bank", which should probably be mentally designated as "everyday use bank" or some such meaningful name :) So you use 2 all of the while, whilst 1 is sitting there, fully charge, just in case.

Those two options assume 1 is the engine battery, feel free to swap 1 and 2. Try both options and see which you prefer ?
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Robert Wilson said:
Amazon
https://www.amazon.co.uk/Durite-Int..._1?ie=UTF8&qid=1539879666&sr=8-1&keywords=vsr
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I have wired a few VSRs up and i know how many wires they need. Again, read the other thread. I'm also tempted to refer you to post #2.

Did i suggest a Durite car system, or was it perhaps a Victron Cyrix-i 120a VSR ? Let's try looking at the correct piece of kit, shall we ?

https://www.victronenergy.com/upload/documents/Manual-Cyrix-Battery-Combiner-Kit.pdf

Ignore the start assist cable, that leaves 3 wires.
 
PaulRainbow said:
You still need to fiddle with 1-2-B switches and still have no way of charging both batteries via the alternator at the same time.
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Won't the normal practice of setting the switch to 'B' when the engine is running charge both batteries from the alternator?
 
Robert Wilson said:
I'm tempted to myself, too!!

I have put the delivery of the Photonic until next week so that I can my head round it all.
And lw395's post #27 has me even more confused!

Thanks for your patience, all of you.
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Please, ignore post #27. He's either trolling or has bumped his head on something hard. :)

I posted in detail why leaving 1-2-B switches on both is bad practice.

You might have noticed that there are a great many threads on here about electrics and in particular battery and charging systems. That's equally true in the real World and a large part of what i do for a living involves designing and fitting those systems. People will write on here how they've used method so-and-so for 3 decades and it's worked fine, even though it's not the correct way of doing things. That may well be very true, but i get to see a hell of a lot of boats, usually when they've gone pear shaped. Some common reasons for things going badly relate to 1-2-B switches, typically people using them incorrectly. You can use them on the "Both" setting perfectly OK, providing everything is tip-top onboard and nothing goes wrong.

I have three boats within spitting distance of where i'm sitting now that have 1-2-B switches, both of them have issues this year. I had previously suggested they were not a great system. Two of them accidentally left the switch on "Both" and discharged the batteries to the point where the engine could not be started. These are booked in for revised systems.

The third one sits two boats away from me. I had recently advised the owner against leaving the switch on "Both". Two days ago, he went to start the engine but it would not turn over, the engine battery had failed. Luckily he had heeded my advice and had not been using the switch on "Both", so he was able to start the engine from the domestic bank. I'll be fitting new batteries tomorrow and she's booked in for a revised system too.

I firmly believe that separate circuits are the best way forward, with suitable split charging arrangements, but i understand that not every has the budget or desire to replace what they have, even if they do accept that separate circuits are better. For those people, i try to suggest what i feel is best for their setup.

In your case, as with Daves, considering neither of you wants to ditch the switch, i think a simple VSR makes for a much better system than you have, for the reasons i posted earlier. Not least of all, no fiddling with the damn switch :encouragement:
 
Robert Wilson said:
I have put the delivery of the Photonic until next week so that I can my head round it all.
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Considering the time of year, I get the impression that you perhaps are looking for a simple, DIY system that will see to it that both batteries are maintained over winter when the boat is not in use?
That is, not really for recharging, but only to counter self discharge or some very low loads.
During the sailing season the demands would be different and require an other the set up.
Just an idea: Get the dual output controller and connect one output to the house battery terminal on the 1-2-B switch. The other output goes to a SPDT switch, which is connected 1) to the engine battery terminal on the 1-2-B switch and 2) to the other output terminal on the controller.
So by flicking the SPDT switch you would either let the solar panels charge both batteries or let both outputs feed into the house battery. The former would be the "winter position" of the SPDT switch, the latter the "summer position".
This is based on the idea that during summer, when the engine is run, there is really no point in feeding solar charge into the engine battery.
 
PaulRainbow said:
Please, ignore post #27. He's either trolling or has bumped his head on something hard. :)

I posted in detail why leaving 1-2-B switches on both is bad practice.....:
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Yes but it was bullshit.
When the engine is running, if the two banks are connected together by a VSR, it's electrically the same as being in 'Both' as far as the solar charger is concerned
 
lw395 said:
Yes but it was bullshit.
When the engine is running, if the two banks are connected together by a VSR, it's electrically the same as being in 'Both' as far as the solar charger is concerned
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Of course it isn't, you're just talking more nonsense. I'm pretty sure you are not this stupid, so i'm leaning towards trolling.
 
lw395 said:
Yes but it was bullshit.
When the engine is running, if the two banks are connected together by a VSR, it's electrically the same as being in 'Both' as far as the solar charger is concerned
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There may be a problem with using the dual output solar controller recommended earlier in the thread toether with a 1,2 both switch

The instructions contain the following passage:

Overview

This dual battery solar charge controller is designed to charge and protect
two independent 12V or 24V batteries or battery banks (e.g. engine and
leisure battery) using energy from solar panel(s). Both batteries should
have the same voltage, but they can have different capacity.

Note: independent charging assumes that batteries should be
electrically isolated from each other, i.e. they should not be
connected to the same system. Several batteries connected in the
same battery bank should be treated as 1 battery when using this
solar controller.​

I am not sure though if this is merely pointing out that the batteries will not be independently charged if connected together or if it is warning that the two controller outputs should not be linked, eg with a 1, 2, both switch.
 
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VicS said:
There may be a problem with using the dual output solar controller recommended earlier in the thread toether with a 1,2 both switch.....

I am not sure though if this is merely pointing out that the batteries will not be independently charged if connected together or if it is warning that the two controller outputs should not be linked, eg with a 1, 2, both switch.
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Equally applies to connecting the two outputs together with a relay, VS or otherwise.
I did suggest clarifying this with the supplier....
 
lw395 said:
Equally applies to connecting the two outputs together with a relay, VS or otherwise.
I did suggest clarifying this with the supplier....
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You've clearly lost the plot. The OP in this thread did not have a dual output controller or a VSR. He was considering fitting a switch. I suggested a VSR would allow his existing solar controller to charge both banks. It would also allow the alternator to charge both banks too, without having to mess around with the 1-2-B switch.

A Victron VSR costs less than the suggested dual output controller.

Fitting the dual output controller put the OP in the same boat as Dave, from the other thread.

Now, back under your bridge.
 
Sorry I can't clear up about the Dual battery controller. I e mailed twice, yesterday and the day before, very specifically and for whatever reason Photonic Universe have not replied. It was maybe the style of my e mail but they "can't comment" on external wiring is what they said in an earlier but related e mail.
 
PaulRainbow said:
You've clearly lost the plot. The OP in this thread did not have a dual output controller or a VSR. He was considering fitting a switch. I suggested a VSR would allow his existing solar controller to charge both banks. It would also allow the alternator to charge both banks too, without having to mess around with the 1-2-B switch.

A Victron VSR costs less than the suggested dual output controller.

Fitting the dual output controller put the OP in the same boat as Dave, from the other thread.

Now, back under your bridge.
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But any solar installation which can afford the wasted current of a VSR will probably need a controller of some sort.
Plus battery isolators and cables...
 
lw395 said:
But any solar installation which can afford the wasted current of a VSR will probably need a controller of some sort.
Plus battery isolators and cables...
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So, what's your suggestion for allowing a solar controller to charge both banks, the alternator to charge both banks and for there to be no fiddling with 1-2-B switches ?
 
Robert Wilson said:
So, in plain language please, IF I now fit the PhotonicU controller, what happens when I'm running the engine/alternator using the "1 or 2 or both" position(s) on the changeover switch and have my two solar panels connected to the PhotonicUniverse controller?
Click to expand...
Solar controller is a fit and forget wired direct to batteries.
Alternator wired to 1-2-both doesn't change and is used just as you always have.
You can get more sophisticated, but you don't HAVE to.
 
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