Multiplus II ignores absorb settings and keeps overcharging my LiFePO4 batteries

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Paul asked Jan 28, '23

Multiplus II ignores absorb settings and keeps overcharging my LiFePO4 batteries

Hi everybody.

We have a Multiplus II 5000/48 combined with a 52V 160Ah LiFePO4 battery controlled by a Batrium Core1 BMS communicating over CAN to the VE.CAN bus.

After I removed 10pcs Enphase IQ7+ from the garden house roof, I connected the 10 pcs AEG 365Wp panels in a 5s2p config to the SmartSolar 250/100.

ESS agent is running with absorbtion voltage at 53,6V and float on 52V

Whatever, however and whenever I do, the Multiplus - even with a de-activated charger - KEEPS pushing my batteries over their limits like blixen and thunder pulling the sleigh without Santa Clause controlling them.

I know bulk throws 56,8V at my batteries (somewhere between 55,5 and 56,5) but this SHOULD change into absorbtion when the batteries have reached at 53,6 Volt.

I disabled DVCC, although the CANbus from my Batrium BMS nicely shares Voltage, current and temperature to the portal.

I am kind of getting frustrated and at the moment very reluctant of expanding the MultiplusII with two brothers and some pylontech batteries......

Any help would really be appriciated!

Multiplus-II

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Answer 1 · 2023-01-29T05:50:39Z

snoobler answered · Jan 29, 2023 at 05:50 AM

Include screenshot of your Batrium Remote tab

Include your MP charger settings.

Include your ESS assistant settings and GX settings.

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Answer 2 · 2023-01-29T13:20:16Z

@snoobler thanks for coming to the rescue here, I am more and more aware, I miss the real insights of the basic functionality of the CANbus cooms and SOC info shared between Batrium and Victron.

To start: I corrected the remote settings that didn't matter until the CANbus comms where established between Batrium and Cerbo.

Still: The MP2 ignores the 21% SOC messages from the Batrium and simply says: I have 75% SOC.

Disabling the battery monitor stops the MP2 from changing from bulk to absorbtion, one of my biggest issues here.

Enabling the battery monitor shows 75% SOC which is incorrect!

Where can I reset this value? (I entered specific values for bulk, absorbtion and float here).

Using the SOC setting that has to be respected within the ESS agent, is totally ignored by the victron and the batteries run towards a steep downhill without fence until the Batrium just kicks out the safety relais....

I have a huge sense of Batrium and Victron NOT being compatible anymore but are hoping I just made some mistakes in my settings.

My questions:

A - Shouldn't the Batrium override the SOC settings of the Victron internal battery monitor when it is connected to the BMS.CAN of the Cerbo?

B - How can I reset the SOC values on BOTH devices in order to be synced

C - How can I tell the Cerbo to listen to the Batrium CANbus data in order NOT to try to kill the batteries with an endless bulk mode that overcharges them?

D- How can I prevent the Victron completely depleteing the batteries when setting a desired minimum SOC within the ESS?

Below all the info you requested.

Hope to learn enough to keep the system running stable before buying 20kWh of yellow Winston cells which i don't want to risk...

2023-01-29 Batrium batteries almost depleted.PNG 2023-01-29 ESS ignoring minimal SOC of Batrium.PNG 2023-01-29 ess-1.PNG 2023-01-29 ess-2.PNG 2023-01-29 ess-3.PNG 2023-01-29 finally found bulk settings on MP2.PNG 2023-01-29 what is leading for starting absorption - SOC or voltage.PNG remote page Batrium Core1 BMS.PNG settings MP2 with battery monitor disabled.pdf settings MP2 with battery monitor enabled.pdf schematics.jpg 2023-01-29 what is leading for starting absorption - SOC or voltage.PNG

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