DigitalMind,
Here is something I plan on building but, am in no hurry to construct. Working on a few assumptions, one going to need an inverter anyway, a few AC loads that there just aren't DC options, or maybe something else. Lets just call it 'Basic Inverter for The Control of Home'.
This will be a device to control the inverter and loads. It could be any of several controller chips, PIC, PICAXE or other. The inverter is 'wired on' with this device telling the inverter when to come on. We will use a freezer, refrigerator and water-pump for our scenario.
The controller is 'sleeping'. It wakes on a time-interval determined by climate and observation. It reads freezer temperature and decides the freezer needs cooling. It then turns on the inverter and the freezer. It runs the freezer until the proper temperature is reached. It then looks at the refrigerator. It does the same for it. Finally, it looks at the water level and decides if water is needed.
At all times it checks battery voltages and has set points where things must be done 'manually'. There will be times when battery voltage is high - and one might take the freezer to a lower temperature. This might be done automatically when everything is 'topped off', water and refrigerator, and the batteries are still full. On the 'other end', when there is not as much voltage, the controller would go into maximum conserve mode and the freezer temperature might go up to -5C/20F and the warning lights would tell one the refrigerator isn't being kept as cool as one might care and the rest of the 'bad nuze'.
I do plan on building one of these for my home/shop. However, I am on grid at this time and have little if any need for it. IF I lived off-grid or on a boat, it would be high on my list of necessities. It will allow for less draw as the inverter will never be on when except when using power and should allow a smaller inverter as the loads will be controlled such that no two devices with starting loads are on at the same time.
Ron
