If a cell in your car battery is faulty, it’s likely due to sulfation damage. Sulfation occurs when the battery is left in a low state of charge for an extended period, causing the lead and sulfuric acid to form hard, crystalline lead-sulfate deposits on the battery plates. This can render a cell unusable and lead to overall battery failure.
Repairing a Sulfated Battery Cell
In some cases, it may be possible to reverse the sulfation and restore a damaged cell, but this requires specialized knowledge and equipment. A battery technician can perform a process called “desulfation” to try and dissolve the lead-sulfate crystals. This typically involves applying a high-voltage, low-current charge to the battery over an extended period, which can help break down the crystals.
However, if the sulfation is severe or the cell has been damaged beyond a certain point, the technician may determine that the battery is not worth repairing and recommend replacing it entirely. Attempting to repair a heavily sulfated battery on your own can be risky and may cause further damage.
Replacing a Faulty Battery Cell
If the battery technician determines that the battery cannot be effectively repaired, the only option may be to replace the entire battery. This is generally the recommended course of action if multiple cells are damaged or if the battery is several years old and has reached the end of its useful life.
Replacing a single cell in a car battery is not recommended, as the remaining cells may be unevenly charged and lead to further issues. It’s best to replace the entire battery with a new one that is compatible with your vehicle.