# Solar energy is the lowest cost renewable energy

- Feb 15, 2019-

The main technical parameters of the battery are voltage and capacity. The voltage refers to the rated voltage of the battery, that is, the normal working voltage, and generally has 3V, 6V, 12V, 24V, 36V, and the like. Capacity refers to the ability of the battery to store electricity. Generally, 4AH, 6AH, 12AH, 20AH, 40AH, 60AH, 120AH, etc. are commonly used. For example, in the case of a 40AH battery, it means that when the battery is charged with 4A current, it can be fully charged for 10 hours; if it is charged with 1A current, it takes 40 hours to be fully charged. The reverse is also true when discharging. Under normal circumstances, the charge and discharge time of the battery is preferably 10 hours of charge and discharge rate. When the battery is charged by the solar battery, the voltage of the solar battery should exceed 20%-30% of the working voltage of the battery to ensure normal charging of the battery. If you need to charge 8V battery for 8V battery, you need to use 15-18V solar battery for charging 12V battery.

As for the use of solar panels to charge the battery, how to match is good, mainly to see your actual needs. If it is used in ordinary households, it will use solar energy to charge the battery during the day and lighting at night. For example, the battery is 40AH battery, the solar battery is 305*457MM (15V400MA), 10 pieces are connected in parallel, the voltage is 15V, the current is 4A, then the battery can be filled in 10 hours. If 20 pieces are connected in parallel, it can be filled in 5 hours. The same 400*200MM (10W) monocrystalline silicon solar panel is connected in parallel with 5 pieces, the voltage is 18V, the current is about 4A, and the 40AH battery can be filled in 10 hours.

Solar cell 305 * 457MM (15V400MA), power is about 5 watts, power = voltage * current (P = UI), 10 pieces of parallel 50 watts, charging 10 hours during the day to charge 500 watt hours. In the evening, a 100-watt bulb can be used, and electricity is used for 5 hours, that is, the power consumption is also 500 watt-hours. If you use 200 watt appliances, you can only work for 2.5 hours.

When charging a battery with a solar cell, it is preferable to add a rectifier diode to the charging circuit to ensure that the battery will not be reversely discharged through the solar panel at night. If the charging and discharging automatic protector is better installed, it can ensure that the battery is not overcharged or overdischarged, which is good for extending the life of the battery. The life of the battery is generally 1-2 years.

To use 220V appliances, use a dedicated inverter power supply.