Car batteries usually work reliably for their entire expected service life. However, some batteries may develop defects that may compel you to replace that battery long before the end of its expected life. This article discusses some of those irreparable battery defects.

High Self-Discharge

Nearly all batteries lose some of their charge even if no load is attached to them. For example, the charge level on your car battery may decrease even if that car doesn't have any accessories turned on. This loss of charge is called self-discharge. Some car batteries can exhibit a high self-discharge when compared to the normal self-discharge rate. Such elevated levels of self-discharge can be caused by several factors, such as high ambient temperatures. Batteries that have a high rate of self-discharge should be replaced because this problem cannot be fixed. A technician can use a battery analyser to diagnose this problem. Replace the battery once he or she confirms the defects so that other components of the charging system, such as the alternator, don't wear out quickly due to working with a defective battery.

Cell Mismatch

It is also prudent to replace a car battery when a technician discovers that the cells of that battery are mismatched in terms of their capacity. Car batteries have components called cells. These cells are responsible for the reactions that take place to generate electrical power. A weaker cell can be discharged quickly while the other cells still have some charge on them. Once charging commences, the weak cell starts overcharging when it reaches its full capacity while the other cells are still taking on more charge. The weak cell will then begin overheating. This overheating gradually weakens all the cells until the battery fails. Replace the battery as soon a battery analysis reveals that the capacity of the cells differs.

Loss of Electrolyte

Batteries that keep losing their electrolyte need to be replaced because those batteries are now unreliable. The lost electrolyte forms deposits on the battery terminals. Such deposits increase the resistance within the electrical system. Consequently, you can start experiencing intermittent electrical system failures. Topping up the electrolyte with water cannot fix the underlying problem. Battery replacement is the only way to restore normalcy to the electrical system. It is advisable to have the battery checked thoroughly each time you have your car serviced. That battery inspection will detect those irreparable defects before the defects cause costly damage to the electronic systems and accessories of your car, such as the engine electronic control module.