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lawrence-craig avatar image
lawrence-craig asked

Orion Isolated Wiring with Shunt

Hi all. I have a feeling I have purchased the wrong type of Orion (I bought Isolated instead of non-Isolated). However, I currently have no way to return the device.

I am installing it on a boat where I have a starter battery powered by an alternator, and then a house Lithium bank.

This is how I am thinking of wiring it, but I have a feeling I am creating a short by having the -ve combined as opposed to isolated.

Can you advise on the below? (Please excuse the shoddy diagram)

Many thanks.


1681980646563.png



SmartShuntorion-tr smartorion dc-dcorion
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3 Answers
JohnC avatar image
JohnC answered ·

Hi @Lawrence Craig

It won't matter if you combine the negatives externally, at least if both are at 'zero' potential. The batteries just won't be truly Isolated.

Might be just your diagram, but you appear to make that connection just above the -ve terminal of the starter batt. You'll need to rethink that if you want the shunt to measure just the Li batt.

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lawrence-craig avatar image lawrence-craig commented ·
Hey John,

thanks a lot for that.


The -ve of the Starter & Li batt are connected together and the connection of the Orion -ve is on the starter battery. That's what I am thinking the issue is. Can you provide your thoughts on this?


For info, the +ve of the Starter also goes to a switch and then the engine, it will not be connected at all to the Li circuit, it is isolated.

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klim8skeptic avatar image klim8skeptic ♦ lawrence-craig commented ·

orion-iso.png

Keep your batt negatives separate, and your loads and chargers on the system side of the shunt, then you are all good.

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lawrence-craig avatar image lawrence-craig klim8skeptic ♦ commented ·
hmmm.. thats what I thought. Looks like I will have to isolate the starter battery in that case. A job I am trying to avoid as its a royal PITA to do.
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JohnC avatar image JohnC ♦ lawrence-craig commented ·
@Lawrence Craig

You haven't said what your 'issue' actually is. But I can imagine the shunt isn't measuring correctly. The Batt terminal of the shunt should be solely connected to the Li batt -ve. If you want to combine the 2 batt -ve's, do it on the Load side of the shunt.

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lawrence-craig avatar image lawrence-craig JohnC ♦ commented ·
No issue as of yet as I haven't wired it together yet. I think the issue I have is that I think I am using an isolated DCDC charger when I should be using a non-isolated charger. So I wanted to check in terms of wiring that it wouldn't cause any issues having all of the -ves from the Orion on the common negative circuit (instead of the input being isolated from the output).
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lawrence-craig avatar image lawrence-craig JohnC ♦ commented ·
Good point about the shunt though. However, would it still measure the load from the starter battery if +ve from the shunt is isolated from the starter battery?
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JohnC avatar image JohnC ♦ lawrence-craig commented ·
I don't know what you mean by this. A shunt is just a piece of calibrated wire, a -ve wire in this case. And Isolated vs Non-Isolated Orion is something boaties do to try to prevent electrolytic corrosion from stray ground currents. Everything works the same, but it's safer on boats when you may have unknown dc currents from faulty kit.
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lawrence-craig avatar image
lawrence-craig answered ·

I guess my question is: can I use an isolated Orion charger like a non-isolated Orion charger by putting the input and output -ve on the same common circuit?

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JohnC avatar image
JohnC answered ·
@Lawrence Craig

Yes, you can.

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