The basic principles of off grid solar power system:

Off grid solar power system mainly consists of solar arrays, batteries, charge and discharge controllers and DC / AC inverter.

(1) Solar Array:

Solar array is composed by the solar panels connected by a certain composition, its role is to convert solar radiation into electrical energy directly  ,and in sunlight, to provide power for electrical equipment,at the same time charge battery.

(2) Battery:

Batteries are for storage DC power produced by of solar arrays, in the absence of the sun, to provide power for appliance.Generally,we will choose the lead-acid batteries of maintenance-free with¡± depth of discharge is large, self-discharge rate is low, high efficiency of charging and good performance in low temperature.¡±

(3) The charge and discharge controller:

Charge and discharge controller is used to implement the entire system charge and discharge fully automatic control, to achieve the result that solar array  provide the best charging current and voltage battery ,to charge for battery with fast, stable and efficient, and minimize the loss to extend battery life in the process of charging ,at  the same time, to monitor battery power to ensure that batteries are not damaged due to over charging or over-discharge.

(4) DC / AC inverter:

     The role of the inverter is to convert DC produced by square solar cells and batteries to 220V AC, to supply AC for appliance. When the battery voltage DC input voltage is in normal range,and the output load is in rated power range, inverter can work normally in circumstance of 220V AC,but when the load power exceeds rated power of 20% or output short-circuit, it automatic protect circuit, to cut off the AC output and thus ensure the inverter is not damaged.