Batteries are like bath tubs full of electricity, so two factors come into play to answer your question:
1. The total storage (usable) available, ie how many kilowatt hours of electricity are in the battery
2. How fast (at what amperage) can it discharge (a) for startup/surge loads, and (b) how fast can it discharge continuously.
A single Enphase 10kWh or Tesla 12 kWh Powerwall CANNOT reliably operate ANYTHING on a 240V circuit. I have a single battery that’ll handle 16 amps continuous, with somethin’ like 29 AMPs surge for 40 seconds. If you have TWO batteries, then just double that, and you can operate 240V appliances that AREN’t 50 amp circuits. Ya ain’t gonna operate your electric oven or other 50 AMP circuits. You CAN absolutely operate a 110V AC or a 240V AC that is on a 20 AMP breaker. REM: how long you can operate it varies by your total load X hours. On a single battery we could easily run all our 110V critical circuits *AND* add a window unit for the master *IF* we wanted to. We cook with gas and the microwave is a no brainer, as is the coffee maker. Not gonna run the hot water heater til the sun comes up, so just adjust your lifestyle if the grid is down.
240V well pump? run it during the day or have 2 batteries. If you have a modest shallow well pump, then get the electrician to tell you the surge and continuous loads.
In the end, it’s just electricity. IF you aren’t well-schooled in loads, then get the advice of an electrician. 5 minute conversation. If you are looking into solar, Enphase even has an online estimator/ system sizer to help you make good choices.
Note well - a solar battery is PRICEY. And you’d better be a master electrician trained on solar controllers before you attempt a DIY. *IF* your life and health require 240V circuits to operate when the grid is down, then buy the right inverter generator WITH a suitable 240V load capability. That’ll be big bucks, but FAR less than a solar battery.
Remember - I bought the battery with our system NOT to run the house, but to enable SILENT resiliency of critical circuits if the grid is down.
If you still have questions, just post a reply. Thanks.
Thanks.
Best source of info I have found is Will Prowse. He has a YouTube channel, a website, and a book. He covers both home and RV installations. Very knowledgable, very thorough, and very honest.