Charge controllers are made by several manufacturers, including Trace and Ananda Power Technologies. Batteries Most solar electric systems use lead acid batteries to store power for cloudy weather or for nighttime. They can even be re-invigorated if they are abused, for example, sulfation can be reversed, more water can be added, etc. If charged properly, good lead acid batteries will last for decades. However, under most conditions the larger deep cycle batteries last 10 to 15 years.
Batteries are cheap and easy to replace, if they ever do go bad.
In the last 2 years a revolution in inverters has been happening, mainly at Trace Engineering. This firm has responded to changing customer needs very rapidly. Most households run on AC because AC wiring is cheaper and somewhat safer than DC wiring. The AC output of inverters is either a modified sine wave or true sine wave. Most residential systems use modified sine wave inverters, which are somewhat less expensive.