Batteries and Controllers

Solar paneled electricity is rarely used to work electrical equipment directly as the amount collected varies with the sunlight power. Hence, the inconsistent electricity amount is unsuitable for powering most electrical appliances.

The grid tie system inverter is most suited for adjusting this inconsistent power amount as extra demand can be tapped from the grid as well as your solar system. But batteries are required to store the backup energy in a grid fallback or off-grid system. Batteries are best utilized to store generated energy to provide a constant supply of electricity for electrical appliances as solar panels harness the sun’s power best when the sun is shining brightly. The best type of batteries to store the generated electricity would be the ‘deep cycle’ lead acid battery; although functioning similarly to car batteries, they sport a different design on the inside that permits a few hundred times of discharge and recharge. 
 There are two types of lead acid batteries: 6 volts and 12 volts. These can form bigger packs through a series or parallel connection, similar to the solar panels. A series connection allows the capacity to be larger while a parallel connection maintains the voltage with an increased capacity.

Controller

A controller is usually required to handle the electric flow in and out of the battery, unless a grid tie system is used.

Appropriate care must be given to batteries in the battery pack to ensure their durability and good functioning. Overcharging, even by the solar panel or a complete discharge can cause irreparable damage. The solar system need not use a controller all the time; for example, a small solar panel for topping up the car battery to keep it in pristine condition during the unused periods of a car will not damage a fully charged battery.

But the majority of solar electric systems’ applications do need a controller to handle the battery’s charging and discharging functions in order to maintain the battery pack well.