question

the-doon avatar image
the-doon asked

Controlling Cerbo relays to turn on cell balancers

Hi, I’m trying to control my cell balancers via the Cerbo relays but am struggling to find how to. I tried using generator stop/start but the voltages are the wrong way around to accept high voltage rather than low voltage. I need to switch on a relay at 13.8V and then switch it off again at 13.7V. Is there a way it can be done? I also have a SmartShunt, Multiplus 12/2000 and 3 of 100/30 SmartSolars in the system.

cerbo gx
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4 Answers
Paul B avatar image
Paul B answered ·

I have used a BMV 702 s relay and used the high voltage alarm

or

using the virtual switchs is the multiplus you should be able to turn the aux1 on and off with the setting you are looking for .


I have never done it myself but this may work for you

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1 comment
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nickdb avatar image nickdb ♦♦ commented ·
But isn't VS disabled if the system is using ESS?
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mark232 avatar image
mark232 answered ·

it is better to use node red in cerbo ?


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the-doon avatar image the-doon commented ·
I’ll have a look. Thanks.
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Alexandra avatar image
Alexandra answered ·

@The Doon

The solution is really going to be based on what your comfort levels with node red or if you need a simpler solution and what components you have.

To be honest the voltage based trigger on the BMV suggested by @Paul B is a good option.

You can also do DC voltage based triggers in the inverter relays as well. Programmable relay assistant trigger aux/k1 based on DC voltage or when bulk is finished to start the balancing. Dont forget to set an off condition as well.

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the-doon avatar image the-doon commented ·

Do you know if the inverter relay still works if the unit is in the off position?

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Alexandra avatar image Alexandra ♦ the-doon commented ·
Hmmm. Now you are asking questions.

Logically not. Since off is off.

In the charger only possibly yes.

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the-doon avatar image
the-doon answered ·

Thanks for the replies. I don’t have a BMV so I’ll have a look at the inverter relay. Was hoping to use the Cerbo as it’s easier to get to. It’d be nice to have more control options available. I was also looking to switch on the hot water element when I got a high state of charge.

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Alexandra avatar image Alexandra ♦ commented ·
If you are comfortable to learn or use node red, the options then become almost endless.
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the-doon avatar image the-doon Alexandra ♦ commented ·
I’ve asked if the options I’m asking for can be added to the next firmware update so fingers crossed. I’m sure I’m not the only one who wants to use this feature. I’ll have a look at node red.
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