As mentioned we live offgrid. That means we have no connection to the electrical utility. The power we need is provided by our 9 solar modules and battery bank. There is a charge controller which monitors the charging of the batteries and there is an inverter that converts DC into AC power to run our lighting and appliances.
Our stove, and hot water production are powered by propane but basically everything else is electric.
Living offgrid requires you to think a little differently about your power usage. If the batteries are full and it's going to be sunny for the next day or two then my wife will make bread with the bread maker. If the weather forecast is not great for the next day or two she might wait until the weather is more promising.
We have appliances such as a clothes washer and refrigerator that are highly efficient and are easily run by our system.
The same reasoning goes into doing laundry. If the weather is looking good we will do a load or two of clothes however if it's not great we will try and hold off.
Sometimes we run low on power and tomorrow's forecast is rain so we have to run our generator to charge up the batteries. When you are running the generator for a few hours for charging that's a good time to run the washing machine or bread maker. The generator we have is sufficient to run a few appliance and charge the batteries at the same time.
So... back to the batteries
The style we have are flooded lead acid. It's not new technology but it works well and it is cost effective. Most of the battery banks out there are flooded lead acid with some being sealed AGM batteries. AGM batteries are still lead acid technology but don't require any maintenance.
Our batteries on the other hand require a bit of maintenance every 4-6 weeks. We need to check the level of the electrolyte and add distilled water. At the same time we should be cheking the specific gravity of the batteries and recording it.
Today we replaced the battery caps with "water miser" caps. These are pretty cool. As the hydrogen and oxygen gasses pass through these new caps there is a catalyst inside that allows the gasses to recombine and reform back into water. The water then drips back into the battery. This reduces the water you would need to add by about 50%. This reduces the amount of hydrogen gas being emitted and also cuts down on the amount of corrosive gas coming from the acid in the batteries.