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How Do I Know if My SLA Battery is Dead?

Power - by Bryan Veldboom - updated on 8/4/2021

Many different SLA types

Sealed Lead Acid (SLA) batteries are used to power hundreds of applications, ranging from emergency lighting and wheelchairs to floor scrubbers and data centers. Today we'll be discussing how to get the most life possible out of your SLA batteries and how you know when it's time to replace them.

What is an SLA Battery?

The primary difference between SLAs and other lead acid batteries is that they are sealed. This makes them completely leak-proof and allows them to be mounted in a variety of positions without fear of them spilling. Another advantage is that you don't have to top off the electrolyte inside them with distilled water the way you do with traditional lead acid batteries. This is because the gas produced by an SLA battery is reabsorbed into the battery's electrolyte, eliminating the need for additional water.

How Long Does an SLA Battery Last?

The life of an SLA battery will depend on a number of factors, including what it's being used for, the operating temperature and how well it's been maintained. Battery life is measured in charging cycles. A single charging cycle refers to the process of going from the battery's full charge capacity to a complete discharge. As a ballpark figure, you can expect an SLA battery to last between 50 and 500 charging cycles.

How Do You Maintain an SLA Battery?

Obviously, you're going to want to get the longest life possible out of your battery. Accomplishing that depends largely on your charging habits. For starters, you need to make sure that you're using the right charger. Gel batteries used in solar power, wind generation and communications applications require a different charge voltage than other sealed lead acid batteries. When selecting a charger, be sure that it's rated for your battery's specific voltage.

Be sure to avoid overcharging your battery. Do not speed up the charging time or increase the voltage in an attempt to charge your battery faster. Overcharging leads to overheating, which can kill your battery completely in as little as a few hours.

Undercharging is equally problematic. Do not use a lower charging voltage than your battery requires as this will prevent your battery from becoming fully charged. When a battery is undercharged it has to work much harder than a fully charged one, resulting in a shortened battery life.

SLA Battery Charging & Storage Tips

Follow these suggestions to maintain a regular charge and keep your SLA battery healthy.

  • Recharge your battery after each use
  • Always store your battery fully charged
  • Disconnect the charger immediately once the battery is fully charged
  • When storing an SLA battery, be sure to keep it in a cool, dry place
  • Do not store an SLA battery in a discharged state
  • When storing a battery, check its charge every couple of months
  • If the battery is stored in an area with a temperature above 68 degrees F, it will need to be charged more frequently

Signs That Your SLA Battery is Dying

Even with the proper care and storage, your SLA battery will eventually need to be replaced. If your battery is having trouble holding a charge, you'll want to have it tested to see if it's still viable. If your battery is looking swollen or cracked or you find a buildup of corrosion on its terminals that's a good sign that it's been overcharged. Corrosion can be cleaned off using a wire terminal brush and a solution made out of water and baking soda. Swollen batteries, however, have already been damaged and will need to be replaced as soon as possible.

Have Your SLA Battery Tested at Batteries Plus

Looking for an easy way to tell if your SLA battery needs replacing? Bring it to your nearest Batteries Plus and have it tested for free. Our experts can tell if your battery is still good, or if it's time to invest in a replacement. Want to learn more about SLA batteries? Reference our Sealed Lead Acid Buying Guide or browse our selection of SLA batteries and battery chargers online.

If you own or operate a business, find out how you can save on your next shipment of SLA batteries by opening a free Batteries Plus business account  . You can also read up on other SLA-centric blog topics, including What is the Best Battery for My Riding Toy? and Why Your Business Should Switch to Lithium Iron Phosphate Batteries.

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