Sealed lead acid (SLA) batteries have been a reliable power source for various applications since the 1850s. While sealed lead acid batteries are durable, cost-effective, and have a long shelf life, proper care and maintenance are critical to preventing a shortened battery life. So, how should you maintain sealed lead-acid batteries?
Understanding SLA Batteries
SLA batteries are distinguished by their sealed design, which prevents leakage and allows them to be installed in various locations without worrying about leakage. The gas produced in SLA batteries can be reabsorbed, eliminating the need to replenish the electrolyte, as is the case with traditional lead-acid batteries. This makes SLA batteries a popular choice for a variety of uses. For example, the PS-1270 is a high-performance SLA battery with a voltage of 12V and a capacity of 7.00Ah for applications such as security systems, medical equipment, emergency lighting, and UPS systems.
Proper Maintenance of SLA Batteries
The service life of SLA batteries depends on proper charging and storage methods. Using the proper charger is critical. For example, gel batteries used for wind, communications, and solar power require a different charging voltage than SLA batteries. Make sure your charger meets the requirements for your specific battery voltage.
Avoid overcharging or undercharging as both can damage the health of the battery. Overcharging by increasing the voltage can cause the battery to overheat and fail completely within hours. Conversely, undercharging prevents the battery from reaching its full capacity and shortens its life.
Charging SLA Batteries
There are several ways to charge SLA batteries:
- Constant voltage
- Constant current
- Tapered current
- Two-stage constant voltage
Constant voltage and current-limited charging are recommended for longer battery life and capacity and shorter charging times.
During charging, a DC voltage between 2.30 volts/cell (float) and 2.45 volts/cell (fast charge) is applied to the battery’s terminals. After discharge, the battery voltage may be lower than the applied voltage but should stabilize over time.
The primary objective of any charging method is to control the charge current so that it stabilizes at the end of the charge. For a more detailed discussion of charging, see our Comprehensive Guide to Charging SLA Batteries.
Storage of SLA Batteries
Prolonged storage can lead to battery degradation and aging. Over time, batteries may self-discharge and seals may rupture, leading to water ingress and permanent damage. Proper storage methods can extend the life of SLA batteries.
SLA batteries can be stored for up to two years, provided the voltage is checked regularly and charged when below 70%. Undercharging increases the risk of battery sulfation.
Temperature also affects SLA batteries. Storage at 15°C (59°F) helps maintain a more adequate charge and extends shelf life.
Cleaning and Troubleshooting
Despite careful maintenance, SLA batteries will eventually fail. Therefore, recognizing battery failures is critical. Regular cleaning and troubleshooting will help catch problems early and ensure your application remains efficiently powered.
Corroded or dirty terminals? Dirt and corrosion on SLA batteries can impede conductivity and prevent optimal performance in your application. Typically, corrosion occurs when metal (e.g., terminals, clips) comes into contact. Fortunately, solving the problem of fouling and corrosion is simple. A wire brush mixed with baking soda and water will effectively clean most dirty batteries. Applying petroleum jelly or anticorrosive gel to each terminal will further improve the conductivity between the battery and the clamps. A terminal protector or protective sleeve can also reduce the risk of corrosion and dirt buildup.
How do I know my SLA battery is nearing the end of its life? Despite proper care and maintenance, your SLA batteries will eventually need to be replaced. If your battery struggles to hold a charge, the next step should be to test its effectiveness. Signs such as cracked or swollen batteries and corrosion and buildup indicate that the battery is overcharged and needs to be replaced. Swollen batteries need to be replaced immediately.
Replacing Your SLA Batteries: if your SLA batteries have been stored for too long, are not holding a charge, or show signs of swelling and rupture, it’s time to replace them. Keheng offers a range of sealed lead-acid batteries with reliable performance and consistent quality. These batteries undergo stringent quality control to ensure the highest reliability in various applications.