As your car battery approaches the end of its life, it’s natural to look for ways to extend its usability before investing in a replacement. The internet is filled with videos suggesting various methods to revive a seemingly dead battery, often involving household substances and unconventional techniques. However, understanding the real reasons behind battery degradation is crucial before attempting any restoration. It’s also vital to recognize that many of these DIY “fixes” can cause further damage or pose safety risks without actually improving battery performance.
Fred Wehmeyer, a Senior VP of Engineering at U.S. Battery with over 50 years of experience in rechargeable battery technology, emphasizes the importance of distinguishing between perceived improvements and genuine battery restoration. He notes that while some hacks might seem to show positive results, these are often misleading. A common example is adding Epsom salt to battery cells. According to Wehmeyer, this practice might artificially increase the specific gravity (SG) reading, but it doesn’t enhance the battery’s actual performance because it fails to increase the concentration of sulfuric acid, which is essential for battery function.
“The sulfates in Epsom salt are bound as magnesium sulfate, making them unavailable for the discharge process to lead sulfate, unlike the sulfates in sulfuric acid,” Wehmeyer explains. “If you were to fill a new lead battery with a magnesium sulfate solution instead of sulfuric acid electrolyte, it would have virtually no capacity.” In essence, while Epsom salt might alter a hydrometer reading, it does not restore the battery’s capacity.
Wehmeyer further illustrates this point by comparing it to replacing diluted electrolyte in a discharged battery with electrolyte from a fully charged one (typically around 1.270 SG). While the specific gravity reading might increase, the battery plates remain discharged or sulfated. This action can be detrimental, potentially ruining a battery that might have been recoverable through proper methods.
The Myths of Baking Soda and Aspirin
Another widespread myth involves using baking soda to revive a dead car battery. Baking soda mixed with water is commonly used to clean battery terminals due to its ability to neutralize sulfuric acid and corrosive byproducts. However, Wehmeyer cautions against introducing baking soda directly into battery cells. This action neutralizes the sulfuric acid electrolyte, converting it into sodium sulfate, which cannot participate in the normal discharge reaction to lead sulfate. Consequently, this method permanently reduces the battery’s capacity, which is likely already compromised.
Similarly, the hack of adding aspirin to a car battery, often promoted in online videos, is also ineffective and potentially harmful. Aspirin is acetylsalicylic acid, which breaks down into acetic acid. Acetic acid aggressively attacks the positive lead dioxide plates within the battery, causing irreversible damage and shortening its lifespan. Although this might temporarily show a minor capacity increase, it ultimately leads to rapid battery failure.
The Potential of Pulse Charging for Sulfated Batteries
If a car battery suffers from sulfation – a condition characterized by reduced power and difficulty in achieving a full charge – pulse charging techniques might offer a path to recovery. Sulfation occurs when lead sulfate crystals build up on the battery plates, hindering the chemical reactions needed for charging and discharging. Wehmeyer advises caution, noting the vast array of pulse charging methods and devices available, ranging from DC pulses with varying voltages and currents to AC pulses with diverse frequencies. He warns, “If not executed correctly, pulse charging can inflict more harm than good.”
Despite the risks, Wehmeyer acknowledges that sophisticated and expensive pulse chargers have shown promise in recovering sulfated batteries more efficiently than conventional methods. However, some pulse chargers draw power directly from the battery itself to generate charge pulses, which can further deplete and damage the battery if left connected for extended periods without an external power source.
The Recommended Approach: Slow Charging and Equalization
For those looking to potentially recover a sulfated car battery, Wehmeyer’s best recommendation is to invest in a long, slow charge. Utilizing a battery charger equipped with a reconditioning or equalization charge mode is often the most effective and safest strategy. “Regularly use the equalization charge mode, approximately once a month, on deep-cycle lead-acid batteries to prolong their life,” Wehmeyer suggests. Equalization charges are crucial in preventing sulfation and stratification by ensuring balanced cell voltages and proper electrolyte mixing.
If your charger lacks an equalization mode, a simple workaround is to allow the charger to complete a normal charge cycle and then manually restart it by disconnecting and reconnecting the AC power. This process extends the charging period by an additional 1 to 3 hours, which can aid in recovering mildly sulfated batteries. However, Wehmeyer clarifies that batteries that are beyond recovery due to neglect, wear from excessive deep cycles, overcharging, or extreme deep discharging are unlikely to be revived.
Ultimately, the most effective approach to maximizing car battery life and performance is adhering to the manufacturer’s recommended care and maintenance guidelines. For detailed guidance on lead-acid battery maintenance, consult the U.S. Battery User Manual. Consistent maintenance and proper charging practices are far more beneficial than relying on unproven and potentially damaging restoration myths.
