“Power Assist: Checked
Dynamic Current Limiter: Checked
These are usually not checked, the latter is for generators only.”
Yes, I have a generator – Manual start and connection.
“For the most part no one here can advise you how to optimise the system, only if the basic settings are correct.”
Thank you. Are the basic settings I have posted correct?
“An optimal config depends on your system size and how you use it, then tuning accordingly.”
System size is mentioned. If anything is missing, please advise. Community members will be limited in the responses where adequate information is not provided.
“Your system is quite unbalanced, so there is no optimal config as it will always have trade offs.”
I would like to know if there is a Victron Energy specification/ guideline / best practice for “unbalanced”. I have not seen any minimum and maximum combinations in a datasheet. If there are, please share the link / information.
“You have a largish inverter, with a small battery and small PV array.”
I have had loads peak at 6kW. On a good solar radiation day (recently), the SoC can go from 80% at about 07:00 to 100% at 10:00 with no serious loads. Solar power at this time of the year (27/06/2025) started trickling in the 07:00 – 08:00 slot on the VRB Dashboard System Overview bar chart. Battery Min/Max: 83 – 99% in the 09:00 – 10:00 slot. The 100% SoC is being reached daily weather perimitting.
“This means your ability to discharge the battery outweighs the ability to keep it charged, so it tends to end up with the battery cycling between charging and discharging, and often struggling to remain fully charged for sustained periods - something needed to keep the cells balanced.”
How long must the battery be fully charged for sustained periods? How many hours a day?
Cycling (Charge mode and then inverter mode) – this used to happen before ESS was configured and uploaded. ESS does not appear to work that way and reverts to the grid when the 80% SoC is reached. Very little is discharged from the battery. I was 50W this morning when the SoC was 79% and ESS #1 and #2 were active.
“At an 80% SOC, there is very little self-consumption available to you, so it will not be a very effective ESS.”
Prior to installing ESS, the inverter would cycle between Inverting (solid green LED on the inverter) and Charging. Left hand side LED’s would come on for charging and bulk.
This is not the same with ESS. At that time the Charging a LED would go on and the Inverter LED would go off. Once the SoC go to about 95%, Charging would go off and it would revert to Inverter. This is the cycle it would follow.
“The best you can do is to try validate that 80% is the right minimum SOC, but here in SA, as you are aware, you have to have enough juice in the lithium tank in case of an unplanned grid outage.”
The SoC did not drop below 79% last night and was drawing up to 500W from the grid at times. That leaves some power for when outages occur.
“You will be able to determine how much PV you can reasonably generate, and offset that against your known consumption.”
My estimate has been included in this thread in a reply.
“I would consider increasing the PV (assuming there is space to do so) and ideally adding another battery.”
Yes, there is roof space for another 3kV PV and the RS 450/100 can handle two strings / trackers. I might have to change the way the strings are put together.
“Freedom Won have had issues pairing batteries, so if that is the plan, I would not leave it too late as time can make that harder to do.”
Another Freedom Won 10/8 would be great when the budget permits. Thank you for the advice.
