...batteries are all well and good if you don't have a large power use. For example if you use gas to heat your water and to cook with then you could easily run off a good battery bank for a couple of days.
Once you start using air conditioners and other power hungry devices forget your battery bank. Don't even consider having a swimming pool or spa bath!
Also forget the fancy down lights unless they are LED or you will be in darkness pretty quickly, even then kept to a minimum.
As you write all4One, then comes replacement after maybe 5 years. At the moment all you really have are lead acid or sealed batteries that will give you the option to continually cycle in flattening and recharging.
Going offgrid totally I do not believe is a realistic option unless you have a way to reliably recharge the batteries quickly and in emergencies.
I could run my last boat off the charged battery bank for a little over two days before I had to start the generator. That is with the 12v fridge running, electric toilet use, occasional microwave use through the inverter, basic lighting at night, and of course a radio or with CD's playing for most of the day. I could not run the electric water heater though or it would kill the batteries very quickly.
That's with 8 x 6v big heavy duty batteries in series to produce 12v. The cost of those batteries now around $200.00 each.
If you connected a dozen batteries you would obviously get a longer output but also a much longer charging time... the above would recharge totally over 24 hours at full charge rate.
