SLA Battery Care

It doesn't take much to maintain your sealed lead acid battery and prolong its life.

Maintaining a Sealed Lead Acid (SLA) battery in 2026 is about more than just cleaning terminals; it is about managing the chemical balance of a technology that is surprisingly sensitive to its environment.

1. The Golden Rule: Store at 100% Charge

Unlike Lithium-ion batteries (which prefer to be stored at 50%), SLA batteries must be stored fully charged.

• The Danger of Self-Discharge: All lead-acid batteries naturally lose charge over time. If the voltage drops too low, the battery enters a state of Permanent Sulfation.
• Sulfation Explained: This is when soft lead sulfate crystals on the plates harden into a solid crust. Once hardened, they can no longer be converted back into active material, permanently reducing your battery's capacity.
• Pro Tip: For long-term storage, check the voltage every 3 to 6 months. If a 12V battery drops below 12.6V, give it a freshening charge.

2. Temperature: The "15-Degree Rule"

Temperature is the single greatest factor in how many years of service you will get.

• The Heat Penalty: The standard operating temperature for an SLA battery is 25°C (77°F). For every 8°C (15°F) increase above this, the chemical reactions inside accelerate so much that the battery's lifespan is effectively cut in half.
• The Cold Risk: While cold slows down chemical degradation, a discharged battery can freeze at temperatures just below 0°C (32°F). A frozen battery will often have a cracked internal plate or a "bulged" case, making it a total loss.
• Storage Advice: Aim for a "Goldilocks" zone—cool and dry (ideally 10°C to 15°C or 50°F to 60°F).

3. Fighting Stratification

Stratification occurs when a battery sits unused for too long. The heavy sulfuric acid sinks to the bottom, while the lighter water stays at the top.

• The Result: The concentrated acid at the bottom corrodes the plates faster, while the top of the plates "starve" from a lack of electrolyte.
• The Prevention: Regular use or a modern "Smart Charger" with an Equalization Mode will stir the electrolyte and keep the chemical mixture uniform.

4. Terminal Maintenance: Beyond the Wire Brush

Corrosion isn't just ugly; it's a high-resistance barrier that forces your battery to work harder.

• Cleaning: Use a solution of baking soda and water to neutralize acid salts.
• Protection: After cleaning, apply Dielectric Grease or a dedicated battery terminal protector. Unlike petroleum jelly, these are designed to handle the heat of high-current draws without melting away.

5. Critical Update: Should You Add Water?

The short answer: NO. The modern consensus for 2026 is that you should never attempt to open or "water" a Sealed Lead Acid battery.

• VRLA Design: SLA batteries are "Valve Regulated." They use an internal oxygen recombination cycle to turn gases back into water.
• The Risk of "Opening": Breaking the factory seal introduces outside air, which can "dry out" the fiberglass mats (AGM) or contaminate the silica (Gel).
• Safety Hazard: Forcing water into a sealed unit can cause the battery to rupture or explode during its next charge cycle because the pressure-relief valves may become blocked. If your SLA battery is "dry," it has reached its end of life and must be recycled.

Summary Checklist for 2026 Care

• Do: Use a Smart/Float Charger that automatically stops when the battery is full.
• Do: Recharge immediately after every use; never leave a battery "half-empty" overnight.
• Don't: Let the battery sit on a cold concrete floor (place it on a wooden shelf or plastic mat to prevent temperature-induced discharge).
• Don't: Fast-charge a battery that feels hot to the touch.

Sealed lead acid batteries power or start many of our devices, including motorcycles, boats, wheelchairs and mobility scooters, and much more. A bit of maintenance during their lifespan will increase the amount of time between battery purchases, saving you money and putting fewer batteries into early recycling.