question

mallo avatar image
mallo asked

Passthrough

Hi

I have connected my Multiplus 2 with my shore power going into the input and the output No. 1 going to my distribution board, this means the inverter will supply the distribution board when the shore power is not available.

If I leave the boat for a while I don't want to have the batteries being on-charge all the time, is there anyway that I can turn the charger off on my Cerbo but maintain the pass through to the distribution board.

I haven't set up the Multiplus 2 yet, but would like to know if this is possible??

Thanks for any help you can offer.

Multiplus-IIcerbo gx
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4 Answers
Kevin Windrem avatar image
Kevin Windrem answered ·

It is not possible to pass power through the Multi with it turned off. You could put it in charger only mode in which case AC power will pass through the unit but there will still be idle current consumed by the Multi. That idle power is in the spec sheet.

If you want power to your loads with the Multi completely turned off you will need to install a changeover switch around the Multi.

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mallo avatar image mallo commented ·
Hi Kevin

Thanks for your reply, I am happy to leave it charger only, but can I turn the charger off so that the feed is going through to the distribution panel but it’s not charging the batteries???? My lithium batteries are quite happily sitting at 50% for the winter.

I will charge them up in the spring when I want to use the boat again.

Thanks again for your help.

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Kevin Windrem avatar image Kevin Windrem mallo commented ·
Charger only mode will charge your batteries to 100%. So the only way to completely disable the Multi is to switch it off and to activate an external bypass switch.

Why not just let the batteries stay charged at 100%?

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mallo avatar image mallo commented ·
Thanks Kevin


I hadn’t considered the idle current, so perhaps I need a bypass switch so it could be switched to bypass the multi, but also switch in the multiplus when I do want to use the pass through, do you have any designs/drawings of how this could work??

I think time for a bit more thinking…….

Thanks for your valued input.

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drizzay avatar image
drizzay answered ·

If you want the multiplus to be on but not send power to your batteries you can disable the charger in VEConfig


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1673413446256.png (333.5 KiB)
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mallo avatar image mallo commented ·
Hi Drizzay,

I have noted the facility to turn the charger off with VEConfig, but that isn‘t very handy having to break out the PC every time I want to turn the charger on/off.

It would be much more useful if it could be turned on/off on the Cerbo, after all the cerbo is supposed to be able to control the system.

But thank you for your inpu.

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diamond avatar image diamond mallo commented ·
If you have "over-ridden by remote" checked then you CAN do it from the Cerbo, by reducing the DC charge current to zero.
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klim8skeptic avatar image
klim8skeptic answered ·

If I leave the boat for a while I don't want to have the batteries being on-charge all the time

You could always set the charger to "float" the batteries at 13.2v. Being held at that voltage they wont be at 100% soc, and any charging current will be minimal (only enough current to prevent any further self discharge) .

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mallo avatar image mallo commented ·
Thanks klim8skeptic yes this is an option, and in fact I could set the float voltage lower to stop it charging altogether, but to set the voltages I would have to connect the PC to the VEConfig every time I want to turn the charger on and off.


I was rather hoping that there was a way of doing this with/through the Cerbo, after all this unit is designed to control the system…..

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Kevin Windrem avatar image
Kevin Windrem answered ·

I don't know if this will work but DVCC allows you to set the max charging current. You could maybe set this to 0.

BTW, lead acid batteries SHOULD be on trickle charge all the time to prevent sulfation. My LFPs can remain fully charged according to BattleBorn.

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