I am installing a home battery storage system, no pv. I thinking of installing a Multiplus II. I will charge batteries at low off peak rate, Octopus Go and discharge batteries at peak rate. If load on AC1 increases when I switch on the kettle, immersion heater and heater to higher than the battery side of the inverter's limit, will it pass through grid AC to meet the excess load? I do not want to rewire the house to use the AC2 output.
Hi, this should work. There are two szenarios implemented. "Power Assist", this means you support a limited grid power by inverted battery power and the "Ignor Grid" where all power will come from inverted battery power as long as possible and only if not possible anymore it switches to grid until it gets possible again by battery. But I do not know if this works as dynamic as the Power Assist! I think the Ignor Grid will completely switch to Grid as soon as the Inverter gets overloaded or the battery empty. The "max feed through current" -see specs - is the limit for grid power to be feed to AC1 Out. But this is anyhow quite high.
Hi, It should work the same as ours which is when insufficient power from solar, and from the inverter it just draws as required from the Grid. Even though ours shows the load going through the inverter its actually connected in Parallel to the grid (connected via AC1 with nothing connected to AC out) - this is because we are using an external current sensor.
Our plan is to also use the Octopus Go night rate to top up the batteries in the Winter when the solar fails to keep up.
Do you mean nothing connected to AC2? Do the grid and battery work simultaneously to meet the above 5kW load, with grid just topping up the excess demand over the battery's capacity? For example if there is 6 kW load the battery provides 5kW and grid 1kW? If it just switches to grid then when someone puts the kettle during peak your paying 6kW x 40 pence instead of 5kW at 8 pence and 1kW at 40 pence, my Go Faster rates.
You would use ESS and the scheduled charging feature to control when the battery can discharge/charge. That is the simplest way. Depending on how complicated your schedule is, you can also use node red to develop some additional automation but this shouldn't be needed.
