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

Robert Wilson

Robert Wilson

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Is it OK/safe to have both batteries permanently connected to a common negative pole on an isolator switch?

I'm thinking of a "DIY" arrangement with isolating rocker switches to allow the charge from my solar panels to go to battery 1, or battery2 or both batteries 1&2 - or both OFF.

As a minimum I'd need two switches, one in the positive wire to each positive pole.

Is there a danger if connecting both negative poles to the single negative on the panels' control monitor?

I reckon five switches would be the dog's bollocks and keep everything isolated, but it would be cumbersome, messy and liable to error (unless idiot proof marked!!)

TIA

P.S. The same question would apply if I bought a standard battery change-over switch.
 
Robert Wilson said:
Would you care to comment further, please?
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I read your question as implying zero understanding of electrical circuits.
I'd advise either not messing with electrics or learning the basics before touching anything.
Although it's only 12V, it can do damage, and the consequences of it not working can be serious.
 
Robert Wilson said:
Is there a danger if connecting both negative poles to the single negative on the panels' control monitor?
Click to expand...

If I understand correctly what you are aiming at, and provided you have a normal two battery system, the negative poles of your batteries should already be interconnected with a large cable? So you would only require one negative wire to the solar controller.
 
Robert Wilson said:
I accept what you say, and I have the basic understanding of circuitry. I just wanted to check that two wires connecting the negative poles of two separate batteries was not going to cause a problem.

Hey ho.
Click to expand...

Fit two switches and connect the positive from the solar controller to one side of each switch. From the other side of each switch you connect a wire to each battery.bank. The negative from the contoller goes to both batteries/banks. As BabaYaga said, the negative from each battery should already be connected together.

I assume you have a 1-2-B switch ?

So, if that's the case, why bother with your proposed switching ? Why not just fit a VSR, which will allow all batteries to be charged by the solar panels or the alternator, without fiddling with the switch ?
 
I find it hard to fathom the logic whereby one has to go away and learn how to do something, before coming here to ask how to do it :confused:[/QUOTE]

Well put. I think there is a time for text books and I'd love to understand things from the basics up. But equally I have studied Nigel Calder, I've done the Tony Brooks website. Both really good and helpful. Other times I want a quick answer and the forum is an interactive stimulating way of learning. Big books and sadly I'm often nodding off and none the wiser.
 
FairweatherDave said:
I find it hard to fathom the logic whereby one has to go away and learn how to do something, before coming here to ask how to do it :confused...

Well put. I think there is a time for text books and I'd love to understand things from the basics up. But equally I have studied Nigel Calder, I've done the Tony Brooks website. Both really good and helpful. Other times I want a quick answer and the forum is an interactive stimulating way of learning. Big books and sadly I'm often nodding off and none the wiser.
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There is a huge danger in assuming the basic competence of someone you've never met.
There is big potential for talking at cross purposes in a forum.
Good advice can easily be taken out of context by people who don't understand the basics that we take for granted.
If somebody doesn't understand that you only generally need (or want) to switch one side of a 12V circuit then I'm out of it, I don't want to give them false confidence which ends in tears.

If I gave someone information which they took out of context and damaged their boat, I'd be upset.
I've seen burnt wiring in boats.
 
lw395 said:
There is a huge danger in assuming the basic competence of someone you've never met.
There is big potential for talking at cross purposes in a forum.
Good advice can easily be taken out of context by people who don't understand the basics that we take for granted.
If somebody doesn't understand that you only generally need (or want) to switch one side of a 12V circuit then I'm out of it, I don't want to give them false confidence which ends in tears.

If I gave someone information which they took out of context and damaged their boat, I'd be upset.
I've seen burnt wiring in boats.
Click to expand...

Ooops. Apologies. I really wasn't targeting you by quoting Paul. I get a huge amount out of the things you have written. Very aware this is the internet. I'm pretty cautious about what I actually do, and always cross reference if in any doubt.
 
FairweatherDave said:
Ooops. Apologies. I really wasn't targeting you by quoting Paul. I get a huge amount out of the things you have written. Very aware this is the internet. I'm pretty cautious about what I actually do, and always cross reference if in any doubt.
Click to expand...

No apology required.
 
BabaYaga said:
If I understand correctly what you are aiming at, and provided you have a normal two battery system, the negative poles of your batteries should already be interconnected with a large cable? So you would only require one negative wire to the solar controller.
Click to expand...
This is something about which I had completely forgotten.
Had I remembered I probably would not have posted my thread in the first place!
Thanks
 
FairweatherDave said:
I find it hard to fathom the logic whereby one has to go away and learn how to do something, before coming here to ask how to do it :confused:
Click to expand...

Well put. I think there is a time for text books and I'd love to understand things from the basics up. But equally I have studied Nigel Calder, I've done the Tony Brooks website. Both really good and helpful. Other times I want a quick answer and the forum is an interactive stimulating way of learning. Big books and sadly I'm often nodding off and none the wiser.[/QUOTE]

Well put yourself.
I enjoy the interaction of the Forum(s) both for the technical assistance, freely given, and the banter. I'd also like to think I have given both of the same from time to time.
I have made some great friends through the Forum, actually and over the ether.
Good luck with your quest.
 
LadyInBed said:
Far easier and probably not a lot more expensive to fit a DUAL BATTERY SOLAR CHARGE CONTROLLER

http://www.photonicuniverse.com/en/...roller--regulator-for-12V--24V-batteries.html
Click to expand...

Sorted. That solves all my needs, thank you.
And c.£33 inc delivery it's a very affordable item for what it does and the peace of mind. Very neat and it will save a lot of fiddling with switches, wirings and hole drilling :)
Just got to check now my solar panel output to ensure it's within range. 160watts for 12volt system.
:encouragement:

Ordered and on its way!!:D

Thank you LiB
 
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Robert Wilson said:
Sorted. That solves all my needs, thank you.
And c.£33 inc delivery it's a very affordable item for what it does and the peace of mind. Very neat and it will save a lot of fiddling with switches, wirings and hole drilling :)
Just got to check now my solar panel output to ensure it's within range. 160watts for 12volt system.
:encouragement:

Ordered and on its way!!:D

Thank you LiB
Click to expand...


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

So, if that's the case, why bother with your proposed switching ? Why not just fit a VSR, which will allow all batteries to be charged by the solar panels or the alternator, without fiddling with the switch ?
Click to expand...

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.
 
LadyInBed said:
Far easier and probably not a lot more expensive to fit a DUAL BATTERY SOLAR CHARGE CONTROLLER

http://www.photonicuniverse.com/en/...roller--regulator-for-12V--24V-batteries.html
Click to expand...


Given the other current solar thread, discussing the exact same controller you suggested :

http://www.ybw.com/forums/showthread.php?509128-dual-battery-solar-charging-and-1-2-both-switch

i'm a little surprised you'd come up with that suggestion.

The answer was back in post #8 fit a VSR
 
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