A variety of battery types is also available. Make sure that deep cycle batteries, specifically designed for solar use, is used. They last much longer.
To compare batteries, Rand per Amp hour can be used as a rough indication of price, as well as Rand per cycle. Quality and expected lifetime are more difficult to determine.
Factors that shorten battery life are:
- more charge/discharge cycles,
- deeper discharge cycles, and
- higher environmental temperature.
Thus, bigger total capacity (in Amp hour) should lead to longer battery life.
For use with inverter:
The inverters we use cannot function without batteries. These inverters can be set to:
- limit battery discharge, thus extend battery life, and
- switch to use the grid as a backup (thus using the grid as a battery, it is usually cheaper than batteries).
Because batteries have to be used, there will be backup electricity for periods when grid electricity is not available. The amount of available stored electricity depends mostly on the amount of Amp hour of the batteries, and charge status.