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christiangurk avatar image
christiangurk asked

Multiplus II 48/5000/70 charge limited to 50A

Hi,

I have a Multiplus II 48/5000/70 connected to a 14kHw 280Ah 52V LiFePo4-Battery with JK-BMS and Venus OS on RaspberryPi. A 6kWp photovoltaik system is connected AC-coupled on the AC-IN-side. Everything is working great except during sunny periods, the maximum battery charge current seems to be limited to 50A.

1680518671694.png

I checked all settings in VenusOS, all charge limits are set to 100A. VRM portal is also showing these limits:

1680518749249.png

DVCC charge limit is switched off, BMS CCL and DCL are also set to 100A.

I also checked with dbus-spy for any secred 50A limit but found nothing. Checked DC charge limit, but also showing 70A...

1680519047760.png

Downloaded Multiplus II configuration via VRM / Device list / Remote VE Configure and checked settings in VE Configure 3:

1680519131212.png

Settings seem to be correct here (Weak AC input = off, Charge curreng 70A)

Does anybody have any idea what else to check? Would be nice, if I could use the whole 70A charging current in specific situations (short sunny periods) to quickly charge the battery...

I already tried to search other questions about this topic but didn't find a good answer. The limit of 50A seems to be a fixed barrier.

Any help is appreciated.

Multiplus-IIcharge current limit
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1680519131212.png (30.4 KiB)
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5 Answers
christiangurk avatar image
christiangurk answered ·

Found the easy solution for my problem: I performed a restart of the Multiplus-II via VenusOS / Battery Inverter / Advanced / Restart VE.Bus system.
After the restart when I disable the "Limit charge control" switch, the Multiplus-II started to charge my battery with aroung 63A from grid (at 53.3V). This seems reasonable to me.
But thanks to all of you with your suggestions.
My gridcode is for Germany.

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pedaaa avatar image pedaaa commented ·

just had the same issue (my 3phase Multi2 5000 system was self-limited to 70A charge current)


. With the same solution to fix it: reboot the VE-Bus-System.

Now its works again normal.


@christiangurk:

Did this issue came back?! Or was this one time only?

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christiangurk avatar image christiangurk pedaaa commented ·
Hi, seems to be one time only so far. But I have my system in standby for the last couple of days, so didn't check. But seems to work normal after restart.
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nickdb avatar image
nickdb answered ·

Any input current limits set?

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christiangurk avatar image christiangurk commented ·

AC input current limit set to 32A:

1680520831050.png

So no problem here... Maximum input power during these phases with 50A charge current limitations was around 3000W, so less than 16A, so far away from the AC input current limit...

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Peter Buijs - NL avatar image
Peter Buijs - NL answered ·

The JK BMS maybe? It has an adjustable charge limit.


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christiangurk avatar image christiangurk commented ·

Hi Peter,

I checked all BMS settings, they are limited to 100A charge/discharge:

1680597325653.png

I also plotted already the corresponding plot from VRM portal with the BMS CCL/DCL over time, here another example from yesterday:

1680597405124.png

So CCL normaly at 100A, dropping down to around 5A during absoprtion and later going up to 100A over night. So BMS IS regulating CCL correct, but when it is set to 100A, charge current never rises above 50A. So there must be another limit elsewhere.

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1680597405124.png (27.7 KiB)
paulcupine avatar image
paulcupine answered ·

Looks like you have 3 phase PV and single phase multi? Could it be that there isn't excess PV available on the phase that the multi is on?

What rate does the battery charge at if you set ESS to "Keep batteries charged"?

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christiangurk avatar image christiangurk commented ·

You are right, I have 3 phase PV connected to AC-IN of my Multiplus-II. ESS gridsetpoint is set to 0. So ESS tries to "hold" sum of all three phases at grid entry point ("Grid") at zero. So if there is excess power aivailable (-1331W in the first picture) then it should raise the batter charge current by this 1331W, only limited by the 70A charge current limit. That works quite well for all charge currents below 50A. So regulating gid entry point to zero works fine.

To answer your second question (good question by the way) I set the charge limit in DVCC to disabled:

1680602975999.png

Immediatly, the battery is charged with high power, peaking again at around 50A after some seconds:

1680603064312.png

So again, there seems to be a limit somewehere at 50A...

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1680603064312.png (55.3 KiB)
lex33 avatar image lex33 christiangurk commented ·
Bonjour Christian


je suis tomber sur ton post car j'ai eu le même probleme de limitation du courant de charge. toutefois je l'ai résolue en redémarrant le VE.Bus .

aussi en observant le diagramme de ton installation j'avais une question a te poser qui est hors sujet.

Quel type de batterie utilises tu ? je vois que ta batterie a une tension en charge a 54.04v et affiche seulement 64% de taux de charge.

au plaisir de te lire


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ossi avatar image
ossi answered ·

Please try setting the ESS Setpoint to Consumption (+5000W) and check if the Inverter Charges Battery from Grid with higher current.

There is known issue about the three phase counter calculation with threephase PV inverter and single phase MP.

If the inverter doesn't charge with higher currents the Issue/ limit is in the inverter lvl - if the inverter chrages with higher currents, i propapbly know a workaround (which gridcode is activ?)

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Related Resources

MultiPlus-II Product page 

MultiPlus-II Manual

Multiplus-II GX Online Manual

MultiPlus-II 230V Datasheet 

VE.Bus Error codes

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