Introduction to the principle of balanced charging for valve regulated sealed lead-acid batteries.
The balanced charging principle of valve regulated sealed lead-acid batteries (hereinafter referred to as valve regulated batteries) is widely used in practical applications due to their characteristics of saving investment, easy installation, safety and reliability, and easy use. However, due to a lack of understanding of its usage requirements and the use of the old balanced charging system, it poses significant harm to the battery.
(1) Reasons for canceling balanced charging
1. What is balanced charging
The so-called balanced charging refers to the charging of balanced battery characteristics, which means that during the use of batteries, the voltage at the battery terminals is unbalanced due to individual differences, temperature differences, and other reasons. In order to avoid the deterioration of this unbalanced trend, it is necessary to increase the charging voltage of the battery pack and activate the battery for charging.
2. Reasons for not needing balanced charging
Firstly, the concept of balanced charging was introduced in the use of old-fashioned lead-acid batteries. Currently, the majority of valve regulated batteries explicitly state "voltage balancing and thorough conversion". And there is no acid layer formed inside the battery, so there is no need for balanced charging. The definition of the charging voltage for a 2.4V single cell battery is accelerated charging, also known as "FASTCHARGE", rather than "EQUATION". Secondly, balanced charging can cause damage to valve regulated batteries. For most batteries, the balanced charging voltage is a relatively high float charging voltage. At this point, most normal batteries are in an overcharged state. The gas that cannot be recombined forms a certain pressure inside the battery. When the pressure exceeds the threshold of the safety control valve, the valve opens and the gas is discharged from the control valve. In previous battery maintenance, the process of balanced charging was accompanied by adjusting the battery density, which means adding distilled water to replenish the water to maintain the balance of the battery. However, in maintenance free batteries, water is not added under the existing maintenance system, which will inevitably cause the battery to lose water and dry up.
(2) How to ensure the consistency of battery terminal voltage after canceling balanced charging
1. The decisive factor of battery terminal voltage
Firstly, it mainly depends on the concentration of the electrolyte and the material of the electrode plate. When the battery loses water, the electrolyte concentration will inevitably increase, causing the terminal voltage of the battery to rise. Secondly, it is related to the opening of the safety valve. If the pressure of the safety valve is too low, it will inevitably cause the battery to lose water prematurely and the terminal voltage to rise. In addition, the connection status between series connected batteries is different, and insufficient charging may occur during float charging. When the battery encounters deep discharge and then undergoes restorative charging, it is difficult to recover, which will cause the battery terminal voltage to be low.
2. Measures to ensure battery terminal voltage
Since there may be inconsistent terminal voltages in batteries and balanced charging is not allowed, how should we ensure the consistency of battery terminal voltages? Firstly, the consistency of battery voltage should be ensured from the raw materials and production process of the battery. For example, the selection of battery materials, especially the selection of key materials such as electrolyte, electrode plates, and pressure control valves. Secondly, it is necessary to ensure the quality of battery installation and ensure the consistency of battery installation status. For example, the connection method of the battery, the balance of torque, etc. Additionally, attention should be paid to maintenance. For some outdated batteries, it is necessary to perform restorative charging and adjust the electrolyte of the battery appropriately; The working status of the pressure valve should be checked regularly.
