Car, motorcycle, truck, and RV batteries are all the same in one particular way: they eventually die. The culprit in nearly every case is sulfation. Yet sulfation is one of the most misunderstood phenomena in battery use. It is also preventable to some degree.
Sulfation is often referred to as the silent battery killer. It is especially problematic for seasonal vehicles, including motorcycles, boats, RVs, and even classic cars. But by understanding sulfation and how it kills car batteries, you can come up with strategies to prevent it. You can also wisely invest in a smart battery charger/maintainer.
The Nuts and Bolts of Battery Sulfation
The nuts and bolts of battery sulfation are rooted in how a car or marine battery actually works. Take a typical lead-acid battery found in a sedan, SUV, or light truck. It has two lead plates submerged in an electrolyte, usually sulfuric acid. The important thing to note is that the battery does not store electricity. It stores potential (chemical) energy.
When a battery is charging, ions inside move from the positive end to the negative end. During discharge, the ions move in the opposite direction. This reaction produces the electrical charge you get from a battery. But it also creates lead sulfate. When you charge the battery again, the lead sulfate converts back to lead and lead dioxide.
Lead sulfate crystals form during discharge and subsequently accumulate on the previously mentioned plates. When a battery is used regularly, minimal sulfation occurs because the lead sulfate crystals are broken up during charging. But that is not the case with a battery that sits idle for weeks or months at a time. The normal and gradual discharge over that span produces more crystals that lead to more accumulation.
Normal Battery Discharge
A typical automotive battery will lose about 1% of its charge per day. So if a classic car or RV sits unused for days or weeks at a time, its voltage could easily fall below the 12.4-volt threshold considered ideal for maintaining automotive batteries.
A chronic undercharging scenario exists when a vehicle’s battery does not fully recharge. Chronic undercharging is possible even when a car is used daily, especially if the alternator is failing. But a battery that doesn’t get used regularly is more susceptible to this problem thanks to sulfation.
Also note that older batteries are even more susceptible. Repeatedly allowing the battery charge to fall below 10.5 volts only accelerates the process. So keeping the battery fully charged is important to minimize degradation.
How Battery Maintainers Prevent Sulfation
Battery sulfation is a big problem for automotive and marine batteries because it creates issues that are hard to recover from. Sulfation doesn’t just reduce battery capacity; it also changes how the battery functions. Damage from sulfation can lead to:
- Decreased battery capacity
- Shorter lifespan
- Reduced cranking power
- Increased internal resistance
- Excessive corrosion
- Internal plate damage
A battery maintainer helps avoid all of these problems simply by minimizing lead sulfate accumulation. Clore Automotive, makers of the PRO-LOGIX brand of smart battery maintainers say that products like theirs are specifically designed to prevent sulfation.
A battery maintainer monitors voltage continuously. When it drops below a predetermined threshold, the device begins delivering a small charge. At full charge, the maintainer stops charging and begins monitoring again.
This simple process prevents the type of deep discharge that encourages sulfation. But if a consumer is willing to spend a little extra, they can invest in a smart battery maintainer with multi-stage charging capabilities. Either way, sulfation is the silent battery killer that battery maintainers are designed to stop.
