I have been really interested in solar and battery energy storage lately since both have become so cheap. I had wanted to build my own battery for a while now but lithium ion battery tech seemed a little dangerous to put in my garage. But I learned about the newer lifepo4 battery tech and I built a diy 14kwh battery. It's been a lot of fun sourcing din rail mount equipment like breakers and terminal blocks and figuring out cheaper ways to build things like a 100amp automatic transfer switch that is still safe and (somewhat) code compliant (since what is on the market starts around $750 for a general ats). Then I've also followed several YouTubers like Will Prouse and Off-grid garage to find the best Battery Management systems and gotten it all integrated with Home Assistant.
I paired it with a 6kw hybrid inverter/charger that I can later add solar panels to and now have a system that should outperform a Tesla Powerwall in both longevity and capacity. My final cost is around $4k including the hybrid inverter and from what I can tell, the comparable Tesla offering costs around $13k.
I have it setup now to do peak power arbitrage so the batteries charge at night during off-peak ($0.20/kwh) and then the batteries run the whole house from 4pm - 9pm when the rate is $0.54/kwh. This saves around $100 a month on our electric bill so it should pay for itself in 3-4 years while also providing backup power in case of outages.
I paired it with a 6kw hybrid inverter/charger that I can later add solar panels to and now have a system that should outperform a Tesla Powerwall in both longevity and capacity. My final cost is around $4k including the hybrid inverter and from what I can tell, the comparable Tesla offering costs around $13k.
I have it setup now to do peak power arbitrage so the batteries charge at night during off-peak ($0.20/kwh) and then the batteries run the whole house from 4pm - 9pm when the rate is $0.54/kwh. This saves around $100 a month on our electric bill so it should pay for itself in 3-4 years while also providing backup power in case of outages.