# Posted: 3 Feb 2011 11:09
You need batteries to supply the DC power to the inverter. You also need some way to recharge the batteries. If you are only using a small tv or cd player, s lsmp.... you probably do not need 4000 watts output.
The place to start is to total up the se; how many things maximum you'd operate at one time. That will determine how large an inverter. Then total up how many watt hours total would be consumed between battery charges; tat will determine battery capacity required. From that a method of recharging can be computed. A PV system sizing calculator can be found HERE.