Lead-Acid Battery Repair and Protection Explained

Lead-acid batteries typically fail for three main reasons:

Frequent Overcharging or Deep Discharging in Low Water Conditions: This often happens with vehicles like taxis, which operate day and night. These vehicles sometimes continue operating with insufficient water levels in the battery, while the generator keeps charging the battery, causing it to overheat. This leads to the battery’s plates bending and short-circuiting, resulting in battery failure. In cases of overcharging, the electrolyte temperature rises significantly, and at severe levels, the electrolyte boils, causing it to splash and erode the plates. Over time, the lead powder falls off the plates and accumulates. If this powder builds up enough, it will short-circuit the plates, causing the battery to fail. Traditional lead-acid batteries with sulfuric acid solution suffer from this issue too. The constant movement of the vehicle shakes the electrolyte and erodes the plates, causing lead powder detachment. More than 90% of these types of batteries from taxis are irreparable.

Poor-Quality or Refurbished Batteries: These batteries are not manufactured according to national standards, resulting in low-quality plates and electrolyte. They might provide some power when new, but their lifespan is limited, and they cannot be repaired once they are no longer functioning.

Sealed Lead-Acid Batteries: These batteries have a separator (such as wool felt) between the plates, which absorbs the electrolyte. The plates in sealed batteries do not experience the same detachment of lead powder as in traditional batteries. The primary cause of failure is the irreversible sulfation that occurs on the plates. This forms white lead sulfate crystals, which reduce the effective surface area of the plates, diminishing the battery’s capacity. For example, a battery that originally allowed an electric bicycle to run 40 km on a single charge might only run 20 km after some time, and eventually, it may fail to run even 1 km.

Causes of Lead Sulfate Crystallization
There are several causes for the formation of lead sulfate crystals:

Prolonged Inactivity: If a car remains unused for a long time, such as new cars that haven’t been sold yet or private cars where the owner is frequently away, sulfation can occur, preventing the battery from starting the vehicle when needed.
Severe Deep Discharge: This happens when the battery is left in a discharged state for an extended period, such as when car lights are accidentally left on overnight. This is particularly harmful to motorcycle batteries.
Dissecting these sealed lead-acid batteries, you will find that the white lead sulfate crystals have bonded the plates together, making it impossible to separate them. In such cases, the voltage across each cell (typically 2V for a 12V battery with six cells in series) could drop to nearly zero.

Reconditioning Sealed Lead-Acid Batteries
Despite these failures, it is possible to restore these batteries. Modern pulse technology can turn the “irreversible sulfation” into a reversible process. In March 2005, German engineer Bingle and Aochi Power engineers Ray developed a new generation of battery protection products, including a battery repair device. After six months of real-world testing, the results were excellent. Upon disassembling the repaired sealed lead-acid battery, it was evident that the white lead sulfate crystals had largely disappeared. The battery voltage had returned from nearly zero to its normal level, and it was able to undergo standard charge/discharge cycles, with capacity restored to 90%, or even exceeding 100%.

According to reports from the U.S., batteries repaired using this pulse technology can have their lifespan extended by over five times. While we have not conducted such tests on domestic batteries, it is reasonable to expect that for electric bicycle batteries from reputable manufacturers, the lifespan could be doubled after repair.

Battery Protectors and Life Extenders
To further extend the life of lead-acid batteries, we developed a battery protector and life extender in 2005. This device is connected across the battery terminals and is powered by the battery itself, consuming very little energy. The principle behind this product is that every crystal needs a nucleus to form. If there is no nucleus, crystals cannot form. The device generates pulse waves that are applied to the plates, preventing the formation of lead sulfate crystals and effectively “cleaning” the plates. Users of this product report that their batteries provide ample power.

In colder regions, vehicles often fail to start in the mornings due to the cold, but using the protector/extender eliminates this issue, as it ensures the battery remains functional.

Conclusion
Lead-acid batteries, especially sealed ones, can fail due to overcharging, deep discharges, or sulfation of the plates. However, with modern pulse technology and the use of battery protectors, these failures can often be reversed, significantly extending the life of the battery. This technology offers great promise for maintaining and restoring the performance of lead-acid batteries, improving both safety and reliability in various applications, including vehicles and other battery-powered devices.