help me with battery backup system

[theusual_]

I'm looking to invest in a battery backup system to run my whole house for at least a day in the event of a power outage. the power bill says I use about 70 KWh per day.
I want something I can charge with grid power or with a generator, also i'm interested in having it switch to battery power automatically in the event of a power outage.

future plans to charge the batteries with wind and solar, and, if possible send excess to the grid but i dont understand how any of that works. for now i just want to make sure i start with something that will be compatible with these plans.
everyone is trying to sell me things and I'm too stupid to understand electricity to know if they're lying to me.

guys, please help me understand the numbers or what specifically to look for. i dont actually know what 70 kwh per day means. is that 70 wats in a day or in an hour? how big of a capacity am i looking for.
hit me with your insights, thanks!

 

[KingSlime]

The first step is figuring out what “must stay on.” Once you know that, we can size your system realistically. For automatic switchover, look for an inverter with a transfer switch or hybrid inverter like those let you charge from grid or generator now and add solar later.

 

[GreyNull]

Same. I started looking into backups and my brain just shut down when people started talking kilowatts, amps, and inverters. From what I’ve learned, you’d need something huge to actually run your whole house for a day, but you can always start smaller and build on it. I’d focus on getting one that can integrate solar later so you don’t have to replace everything down the line.

 

[Alan]

A daily use of seventy kilowatt hours means your home pulls about that much energy over a full day, so a battery system would need close to that size if you want a full day of backup without help from solar or a generator. Most whole-home setups use a hybrid inverter plus multiple battery packs so you can expand later. Are you trying to back up just essentials or literally the entire house?