ESS ignoring minmum SoC

DIY
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1

I have a Multiplus, a battery with a SmartShunt, and a Victron MPPT all connected to a Cerbo GX. I set up ESS to my desired settings, but it does not behave according to my settings.

I have set “minium SoC” at several different levels and observed behavior. The ESS is set to “Optimized with battery life”. Whether I have minimum SoC set to 90% or 50%, the actual battery percentage falls to ~75% between absorption cycles (which happen once a week).

When the SoC falls below the set level, the “SoC is low” and “Battery life is active” in the details, but the battery continues to drain and wattage from the AC input does not increase to compensate. It is typically in this state for 3-4 days until the next absorption.

Every single part of this system is running the latest available firmware.

Again, right now I have “Minimum SOC Unless grid fails” set to 85% and the current SoC is 79% and falling. If mains power were to fail at the wrong time, I could be down 25% of my battery capacity.

2

Could it be possible that you have configured an AC IN Current Limit, so ignoring the minimum soc and draining the battery is the only option to power the loads?

3

I have maximum input from AC limited to 1600w. The total used by (DC+AC) while the battery is slowly draining is typically less than 100w, and never more than about 400w with what is normally connected.

If I increase the load, the grid wattage does go up, just not enough to maintain the battery. There is almost always 5-25w being pulled from the battery under every single circumstance other than absorption.

4

Here is an example of what happens. Minimum SoC is set to 85%. It even says “Slow Charge in process”, but it doesn’t actually charge.

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