Versatility of Logger V2

I

've the 7.4kWh SolarMD lithium battery with Logger V2 mated to a 5KVA Victron Multiplus II inverter and a Victron Blue Solar 150/100 charge controller. All the components are coordinated by the Victron CerboGX. LoggerV2 controls charging via the CerboGX CAN port and reports battery state.

I've 10x430W east-facing half-cut mono PV modules connected to the Blue Solar. Typically these charge the battery by mid-morning on a good solar day. My day time load is on average 500W so energy is bound to be lost. I intend to increase my storage size to 14kWh but for now I have to find other loads to add during peak. This is where the versatility of the LoggerV2 comes in!

I've developed a Load-Shift Circuit which is controlled primarily by the two relays on the Logger. The shifted load comprises 2x 2kW geysers and ACs. Given the limitation of my Victron at max 4kW I do not run the geysers at the same time (maid might be ironing-lol) to avoid overload warnings.

It was important for me to shift the load based on several variables or states other than time. For instance, the battery SOC plays an important role in determining whether the loads are shifted to the inverter or not.

The Relays are triggered by time periods and battery SOC. If the state of charge is >98% and the time is within a prescribed range a relay triggers and this in turn closes or opens a contractor. the relays are triggered differently as they operate two geysers and ACs. I am therefore able to store excess solar as hot water and if the geysers are heated (thermostat switchs off) I can also exploit excess solar as cool air.

If I have deficit energy from PV, the battery is not allowed to compliment beyond 95% SOC. This is my prefered threshold. Any remaining PV will charge the battery back to 100% on a good solar day.

In the image below, a geyser was running and a 18000BTU AC as well as the house load.

The Logger is very versatile and is working brilliantly for me😍