​How to choose a good quality battery?

How to choose a good quality battery?

Performance requirements of batteries for photovoltaic power generation systems

Photovoltaic power generation systems are mostly established in remote and remote mountainous areas, plateaus, and Gobi. The natural environment is very harsh, and the temperature of the working environment varies widely. Therefore, for photovoltaic development,

The battery in the system has the following requirements:

(1) With deep cycle discharge performance, long charge and discharge cycle life;

(2) Strong overcharge resistance;

(3) Strong capacity recovery after over-discharge;

(4) Good charge acceptance ability;

(5) When the battery is used in a static environment, the electrolyte is not easy to delaminate;

(6) It has the performance of no maintenance or less maintenance;

(7) It should have good high and low temperature charge and discharge characteristics;

(8) It can adapt to the use environment in high altitude areas;

(9) The consistency of each battery in the battery pack is good.

Design method of storage battery capacity for photovoltaic power generation system

To determine the battery capacity, first determine how much power the load connected to the system needs each day; second, how many days the battery needs to store based on climatic conditions. When determining the capacity of a battery, it is not necessarily that the larger the capacity, the better. Excessive battery capacity may also cause problems. This is because when there is insufficient sunlight, the battery pack may be maintained in a partially charged state. This undercharged state will lead to increased battery sulfation, reduced capacity, and shortened life. The general calculation formula for battery capacity is:

C = E · t / (D · η0 · η1) (1)

Where C is the capacity of the battery; E is the average daily power consumption of the load; t is the longest number of hours of unused electricity; D is the allowable discharge depth of the battery; η0 is the charge and discharge efficiency of the VRLA battery; η1 is the inverter conversion efficiency .

Battery failure and short life are one of the reasons that hinder the promotion of photovoltaic power generation systems. After the battery is used in a photovoltaic system, its life will gradually decrease. The main factors affecting its life are: limited charging time, long-term undercharge; small current discharge; overcharge; temperature, etc. According to the special requirements of the photovoltaic system on the performance of the storage battery, combined with the above factors affecting the life of the storage battery, a series of performance improvements have been made on the basis of the original storage battery.