As lead-acid batteries age, their capacity gradually declines. EverExceed, as a global provider of professional energy storage solutions, has long focused on improving battery performance and extending service life. Understanding the internal aging mechanisms helps users operate and maintain their batteries more effectively.

1. Positive Plate Active Material Softening and Shedding

The positive plate of a lead-acid battery uses lead dioxide (PbO₂) as its active material. During long-term cycling, the crystal structure gradually loosens and softens. Eventually, part of the active material detaches from the grid and accumulates at the bottom of the battery. This loss directly reduces the amount of material participating in electrochemical reactions, resulting in a noticeable decline in usable capacity.

2. Irreversible Sulfation of the Negative Plate

During discharge, the negative plate forms lead sulfate (PbSO₄). Under healthy charging conditions, PbSO₄ converts back to lead (Pb). However, frequent undercharging, deep over-discharge, or long storage intervals lead to large and hardened sulfate crystals. These crystals cannot be removed through regular charging, blocking the surface of the negative plate and preventing effective ion exchange—ultimately causing severe capacity loss. EverExceed’s optimized charging technology helps mitigate such sulfation risks.

3. Electrolyte Loss and Deterioration

Lead-acid batteries use sulfuric acid and water as the electrolyte. Over time, water evaporates due to electrolysis during charging, causing the electrolyte concentration to rise. High-concentration electrolyte accelerates grid corrosion and reduces conductivity, negatively affecting battery performance. EverExceed valve-regulated lead-acid (VRLA) batteries are engineered to minimize water loss and maintain electrolyte stability.

4. Grid Corrosion and Deformation

The grids inside the plates support active materials and enable current conduction. Long exposure to acidic electrolyte causes the grids to oxidize, thin out, or even break. As the structural integrity weakens, current flow becomes restricted, and the active material loses support—leading to gradual capacity reduction. EverExceed’s enhanced corrosion-resistant grid alloys significantly improve long-term durability.

5. Separator Degradation and Internal Short Circuits

Separators prevent the positive and negative plates from contacting each other. Over extended use, they may age, harden, or develop pores due to heat, vibration, or electrolyte corrosion. Once a separator fails, internal short circuits occur, accelerating battery aging and causing rapid capacity loss. EverExceed adopts high-performance separators to ensure safer and more reliable operation over the battery’s lifetime.

Conclusion

Lead-acid battery capacity degradation is the result of complex electrochemical and structural changes. EverExceed remains committed to delivering advanced battery technologies—helping users achieve longer lifespan, higher reliability, and stable performance across critical applications such as UPS, telecom, and power backup systems.