question

soeberl avatar image
soeberl asked

Multiplus 2 Loading Algorythm: Trigger Absorption --> Float by Tail Current of Shunt

Hallo,

I have a question regarding the Loading Algorithm (for LiFeO4) of Victron Multiplus 2:
I'd like to go from Absorption to Float using Tail Current (like the MPPT's can do it)

for Information: I'm also using a smart shunt, it triggers itself via tail current.

I actually think the Multiplus 2 can only go from Absorption to Float after a defined time.
Am I right?

Sadly, that's basically not what I want.

Tail Current woult be the better Indicator to "cut" the charging of LiFeO4 Batteries, in my opinion...


Multiplus-IISmartShuntfloat
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2 Answers
Alexandra avatar image
Alexandra answered ·

@soeberl

Can we assume you are not using ESS here?

There is the option to use the sustain, where solar finishes off the charge cycle.

For the MP2 you can choose a fixed curve or an adaptive curve for lifepo4. So depending on depth of discharge the absorption time varies rather than a fixed time.

https://www.victronenergy.com/media/pg/VEConfigure_Manual/en/charger-settings.html

If you have a GX the ve bus SOC is synchronised to the shunt anyway. So works alot better.

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soeberl avatar image
soeberl answered ·

Thank you for your fast answer.
And also my bad english - I'm not using it very often...

Yes, I'm running a ESS System, 3x Multiplus II, 2x AC coupled Fronius Inverters, 2x MPPT on DC side.
Victron System running DVCC.
Loading is regulated by the Multiplus II Algorythm.

Everything works fine together.

SOC calibration with the Shunt is also as designed - just fine.

my wish for "fine tuning":
I only want te cells to remain as short as possible on the absorption voltage.
Therfore I wold like to use the tail current from the shunt to trigger FLOAT
(= lower Voltage = good for remaining the cells rest of the day until dawn and usage)


As in your link shown this is sadly not possible for the Multiplus.
(MPPT's in "stand alone" could do it)


Am I right?

thank you!


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