The following factors determine how the PV panels are matched to the batteries

the power generation performance of the panels, the power consumption of the load, the minimum cloudy interval and the duration of continuous power supply to the load in real situations.

For example: the PV panel is 1000 watts, the household load power is 1 kWh per day, and the minimum annual average cloudy day interval is 3 days, so the system load power supply is guaranteed for 5 consecutive days. Analysis is as follows: 1000 watts of photovoltaic panels, theoretical power generation is 1 kWh / hour, but the heat transmission will produce losses, so the actual power generation is 0.8 kWh / hour, if the effective full-load power generation for 4 hours a day, then the power generated by the photovoltaic panels for a day is 3.2 kWh, household electricity is 1 kWh / day, the remaining power is 2.2 kWh / day. If the power supply capacity of the battery to meet 5 consecutive rainy days, the battery loss is 0.2 degrees, then the battery can store 6.25 degrees of electricity, according to the remaining power 2.2 degrees of electricity / day, the battery can be filled in 3 days before the next rainy day comes. According to the analysis, the battery should be selected to store not less than 6.25 degrees