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spidgrou avatar image
spidgrou asked

Switch charger Multiplus ON OFF

Hi everybody,

I've tried to dig into all questions and answer but it seems that my question is never asked before.
If the opposite please my apologise from now. Please send me the link of the previous post.

I'm moving from gel battery to DIY LiFePo4 batteries.
I've just bought a new charger, the Multiplus 12/3000/120.
I've already installed on board BMV712 and Venus OS on a Raspberry Pi3

When I'm in the marina, connected to the shore power, I would like to charge the battery up to 85% of their capacity and switch off the charger, but continue to use the shore power and the inverter if necessary (power off, more energy etc). Then switch ON again the charger at 40% of the batteries capacity.

As I can see the phisical remote can have only Charger ON or Charger/Inverter ON or all OFF.

I see that using the relay of my BMV712, at 85% of the capacity I can open/close the contact and with another bigger relay cut the shore power off, and on again at 40%. But with this setup when the shore power is off I shall would use only the inverter.

Is there any possibility to switch off only the charger function and keep the shore power?

Thanks

Max


MultiPlus Quattro Inverter Chargerchargerswitch
2 comments
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tieman avatar image tieman commented ·

I am in the similar predicament at Max.

Sailing Yacht, Dc coupled system (Multiplus-II 12/3000/120-50, SmartSolar MPPT, BMV 712, Cerbo GX)

While at the marina(dock) I have shore power for AC loads (microwave/water heater). Everything else is 12V and my solar can supply and top off the batteries day to day.

I just want the Multiplus to charge the battery if the solar cant keep up for some reason (it usually can), using SOC from the BMV. I also don't want the multiplus to charge to 100%, would like it to stop at 85-90% for battery health reasons. I am using some SimplyPhi 1.4 12V LiFe batteries (x4, 115AH each, wired parallel), they have a internal BMS, no interface. They recommend reducing DoC to lengthen battery cycle/lifetime.

Right now I setup "VS Ignore AC input" to ignore ac until 50% SOC and back to ignore at 80%. the issue with that is when im on the boat for the weekend (at dock), and turn on the microwave, it inverts and starts draining the battery, while it should just be using the AC passthrough (but cant because I have it ignored until 50% SOC).

I have found no way to change/control the charger function only. although i am new to the multiplus and VE.Configure.

I would be interested in any other options in my configuration.

When sailing and in anchorages, the system works as normal. unfortunately the boat spends more time at the dock then out in the pacific ocean.

-Ty

s/v Pickle Rick

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Matthias Lange - DE avatar image Matthias Lange - DE ♦ tieman commented ·
Did you read all answers?

There is the suggestion of the "charge current control" assistant and DVCC via a GX device.

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3 Answers
Kevin Windrem avatar image
Kevin Windrem answered ·

I don't think there is a way. There is an "ignore AC input" assistant for the Multi but it would disable pass-thru as well as the charger.

You could set the max charging current in DVCC to 0 amps. On bus, that's:

com.victronenergy.settings /Settings/SystemSetup/MaxChargeCurrent

You'd need to write a service that monitors SOC and the charge current to 0 or the real max value.

Why do you want to stop charging at 85%?

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spidgrou avatar image
spidgrou answered ·

@Kevin Windrem thanks for your answer and your help, I will try as you suggest.
Yesterday I continue studying and I'm installing the Venus OS Large where, as I understand, I can manage with Nodered and SignalK some parameters, probably I can found the solution also there.

I have Eve cells, on the datasheet you can see easily that the cells work better and longer if they stay between 20% and 90% of SOC. Also cycles improve.

Thanks
Ciao

Max

s/y Y2K

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mrhappy avatar image
mrhappy answered ·

In VEConfigure there is an assistant called "charge current control". You can set it to swich off the charger completely, allowing passthrough (at least on my multiplus-II, I don't see why it would not be the same on the multiplus) based on different criteria or the state of an aux in-port. An aux-in could be triggered by the BMV relay.

This is how I have that assistant configured:

screenshot-2021-08-23-215255.png


screenshot-2021-08-23-215255.png (179.4 KiB)
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