Looking to get/build a home battery system

[Ruben_20]

Hi all!

I've built 18650 battery packs before, now I would like to install a powerwall type for our house.
I'm looking to get started with ~10 kWh of battery storage with at least a 5kW 3-phase inverter.

The main goal is to charge at night, discharge during the day, there's a 10x price difference so might have return on investment in a single winter.
Looking forward to learn what the go-to inverters are for such use, don't need solar MPPT and all that.

 

[Korishan]

There's a few good builds that have been documented. Check out @Wolf, @daromer, @OffGridInTheCity and a few others in the DIY Battery Project Builds section.

A charge controller type I would recommend would be a hybrid inverter as you have a lot of options to configure these, such as when to charge from the grid. And how much to balance usage between grid/battery/renewable. So you can program them to charge the battery at night when costs are low, and then switch to low, or no, usage from the grid during the day time as long as there is battery capacity.
And considering they also tie in renewable, you can prolong the battery capacity by having a few solar panels, or a whole lot of them, and the controller will keep the batteries topped while solar is available. Some can even do wind input, Midnight Solar is one of these.

A lot of main stream inverters can be connected in parallel to create 3-PH output. They all share the same battery/solar input, and can output to different lines and keep everything synced up. This is nice as you don't "have" to get all 3 units up front if funds only allow 1 unit to start off with. So you could get 1 now, then later down the road get a 2nd unit and tack on, then a 3rd to finish it off. This also helps to drive the cost down a little bit as a fully functional single 3-PH unit can be quite costly to any meaningful amount of power output., 5+kW

 

[italianuser]

Welcome Ruben! Looking forward to see your progress