DIY Battery Storage

This post is a bit more random from my usual. This all started as I was thinking about the "solar generators" you see everywhere and Legion Solar project. Which got me to thinking about a cross. What if you could make something like a solar generator that would feed back into your home system on a schedule. 

Now where I live the utility company offers a time of day program. Where energy outside of peak is cheaper. I started looking at a number of the various options. UPS with a smart plug, legion solar, Solar generator, etc. But I couldn't see anything that would let you run on a schedule.

I like the idea of solar, but it's a bit out of my price range. I liked the idea of a solar generator but that is very device specific. I really like the idea that Legion Solar offers, but the payback just isn't there yet. Which to be honest, they have far better payback period then traditional solar.

Therfore I started digging around. The biggest question I had was around the inverter, traditional inverters are great for standalone but you can't plug that into your utility grid fed outlet. Which led me to a grid tie inverter. I opted for a 12v input model. The reason for 12v.... 1) got it cheap on ebay 2) lowers minimum battery count to one 3) use a standard battery charger.

The whole setup components:

1) 12v Battery

2) 12v grid tie inverter

3) wiring block

4) electrical wire

5) smart plug

6) independently powered smart switch

7) car battery charger

For me I'm going to use Home Assistant to control the automation.

In the end my automation will turn on the smart plug to run the battery charger during off peak hours and turn off the battery to the inverter allowing full power to charge the battery. Then when cheap electricity ends the smart plug turns off the battery charger and turns on the battery to the inverter.