I read this and it turns out what I did was nearly identical. Essentially, I bought 20KWH worth of LiFePo4 48v batteries and connected them to an AIMS 6KW inverter. I run off the inverter, which is connected to grid power. When grid power is present, I still run off the inverter but the inverter is directly connected to the grid. When the grid goes down, the inverter switches to the batteries. My backup is a 5KW gas generator if the grid is down longer than my batteries have energy for, then I start up the generator, which acts like the grid. This causes the inverter to charge the batteries at 60A. This takes about 4 hours to charge my battery bank. I can do this for several weeks. I also have solar panels that can be connected to an MPPT charger. The inverter still powers the house while charging. I just have to be careful that the total load is under 60 amps 220 volts. I turn off the electric stove, dryer, A/C unit and non essential loads to conserve battery power. If you're curious, I back feed the inverter into a 60 amp branch circuit with a lockout mechanism. This eliminates having to buy expensive transfer switches. You can spend a ton of money buying load switching circuit breakers and such, but I'm cheap and don't want to have such a complex system. The AIMS inverter is what is known as a low frequency inverter. I needed this because I have well pumps and septic pumps that have very high startup current. It looks like the guy who wrote article use a high frequency inverter. These are cheap and light, but do not work well for high demand loads like pumps and motors. I went with 48 volt batteries to keep cables smaller. However, now I'm having problems using 12 volt equipment running off 48 volts directly. I don't like using buck converters because the losses are too high. Instead, I have yet another small bank of 12 batteries so I can run 12 volt equipment. I could just plug a 12 volt power supply into the inverter too.