Ess question

Good Day All - after three years, our Victron installation is finally complete and working beautifully. This is the first (of many, I’m sure!) load shedding “episodes” for the system, and I have a question regarding scheduled charging during load shedding: If I have scheduled charging set up for a specific time and we happen to have load shedding during that time, will the system revert to self consumption, or are we going to be left in the dark?

Hi @Ida - Welcome!

The system will revert to Self-Consumption and take the batter up to your set SOC level afterwards if needed!

Welcome Ida.

The system will always keep your loads on as long as it can. It will only switch off when the batteries go so low that they switch themselves off or if you reach a low cut-off setpoint.

All the rest like Min SOC settings and Schedule charge will only come into play while the grid is available.

Apologies. Must have been typing my reply while yours came through.

Thank you!


If I understand you correctly that the Min SOC will come into play, then I have to try and explain it.
The Min SOC will only work while the grid is available. Once the grid fails the battery will discharge pass that point till it reaches a minimum voltage setting or till the BMS protects the cells by disconnecting it. The only way the SOC will come into play is if it is specified in the config file.

Yes and when the grid comes back after load shedding and it find the SOC is below Min SOC it will then charge batteries back to that point. (For the next loadshedding cycle ;))


Onother way would be to think about it this way:
ESS (Energy Storage System) will follow lots of rules (like schedule charging) and stuff to store energy and supply it to you when you want it.
When loadshedding happens your system is not in ESS mode anymore, but more like a UPS island mode. So all ESS rules are out the door until the grid is back up.

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Short answer. When the power is off, then basically all programming and rules that only make sense when the grid is on… will be ignored. That is the basic rule.

So if you asked it to charge, but the grid is down. Well… then it’s not going to charge. Done.

If you told it that the minsoc should be 50%, but the grid is down… well then it will go below 50% if it has to…

If the discharge rate is limited to 50A by the battery (as an example), but the grid is down so it cannot get the remainder from there, and it needs 55A to power the load… well then sorry, it is going to ignore that instruction from the battery and discharge faster than instructed.

Basically, if the grid is out, it runs from the battery until it cannot anymore. And then it switches off.

Precisely. When the grid is out, you’re an off-grid system. And off-grid systems cannot scheduled-charge or have a minimum SOC :slight_smile:

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