How to charge Lead Acid Battery properly?
31 Aug 2021
A battery is an electrochemical device. During the battery discharge process, the stored chemical energy is converted to electrical energy that is used to power an electrical load. The charging process is the opposite reaction, where the electrical energy from the charging source is being stored into the chemical energy of the battery. In this article, we will know about the procedures of charging Lead Acid batteries to maintain their life-span. The lead acid battery uses the constant current constant voltage (CCCV) charge method.
Stages of charging Lead Acid Battery:
With the CCCV method, lead acid batteries are charged in three stages, which are [1] constant-current charge, [2] topping charge and [3] float charge. The constant-current charge applies the bulk of the charge and takes up roughly half of the required charge time; the topping charge continues at a lower charge current and provides saturation, and the float charge compensates for the loss caused by self-discharge.
How to charge:
Before connecting the battery, calculate the charge voltage according to the number of cells in series, and then set the desired voltage and current limit. To charge a 12-volt lead acid battery (six cells) to a voltage limit of 2.40V, set the voltage to 14.40V (6 x 2.40). Select the charge current according to battery size. For lead acid, this is between 20% of the rated capacity. A 10AH battery at 20% charges at about 2A; the percentage can be lower. An 80 Ah starter battery may charge at 8A. (A 10% charge rate is equal to 0.1C.)
Observe the battery temperature, voltage and current during charge. Charge only at ambient temperatures in a well-ventilated room. Once the battery is fully charged and the current has dropped below than 3% of the rated charging Ah, the charge is completed. Disconnect the charge. Also disconnect the charge after 16–24 hours if the current has bottomed out and cannot go lower; high self-discharge (soft electrical short) can prevent the battery from reaching the low saturation level. If you need float charge for operational readiness, lower the charge voltage to about 2.25V/cell.
You can also use the power supply to equalize a lead acid battery by setting the charge voltage 10% higher than recommended. The time in overcharge is critical and must be carefully observed.
When it comes to charging any batteries externally, it is always wise to use a good charger. EverExceed offers integrated high quality industrial rectifier battery chargers with unique design and smart features such as:
• Phase controlled Thyristor technology
• Flexible maintenance and reduced MTTR
• Long design life up to 20+ years
• Full compatibility with Lead Acid and Nickel Cadmium batteries, sealed or vented
• Smart communication and remote monitoring
Our mailbox is always open so if you have further queries and questions about batteries, chargers or anything related. Please feel free to drop us an email.
