ESS using battery when grid is available

[Comeodore (Vladimir)]

Hi everyone,

I have a Pylontech US5000 battery connected to a Victron Multiplus 2 GX. My system is set up according to this manual [Victron & Pylontech]. Here’s my current configuration:

• AC Connections: One grid AC input and one AC output.
• Battery Connection: Linked to the inverter via the original CAN VE cable.

I’ve enabled the ESS Assistant in “Keep Battery Charged” mode. The grid metering is set to inverter/charger, and the grid setpoint is at 0 W. My goal is to use the battery like a UPS—only activating it when the grid is unavailable.

According to the Victron manuals, my configuration should be correct. However, I’m experiencing an issue where the battery is constantly discharging and charging whenever the grid is available.

Thats all time grid is available and can be transfered on ac loads

Firmware is updated

Can anyone help me troubleshoot this or suggest changes to make the battery function as intended?

Thanks in advance!

[lxonline (LX)]

Do you have solar?

[Comeodore (Vladimir)]

No, only grid, inverter and battery

[lxonline (LX)]

Why don’t you remove ESS and just use it with ups enabled?

[Comeodore (Vladimir)]

Because in this mode my battery just discharging (0.1A) in grid when 100%

When i use “On” mode, same situation, battery discharged

And same situation on loads discharge

[alexpescaru]

Leave it as in the first post, just set a grid setpoint a little bit higher. 50-100W
Still, the battery will still slowly discharge, the discussion here is a bit more nuanced, but it’s OK.
When it will hit 99% will be charged back to 100%. This will not hurt the Pylontech.

[lxonline (LX)]

If you inky need a UPS funstion. The ESS assistant is not suitable.
Delete the assistant and just enable ups on the grid tab.
And as Alex mentioned, this is normal behaviour and isn’t actually a problem.