Deep cycle battery: how do you tell if it’s bad?

Deep cycle batteries are a common sight in most households. They’re typically used in marine applications, recreational vehicles, boats, race cars, and devices that use a lot of energy, like digital cameras and portable music players. However, the performance of the battery will degrade as you use it. The rate of battery deterioration varies based on several factors, including external temperature fluctuations, which affect the battery’s condition. This factor usually affects RV batteries and those usually exposed to external conditions.

Other factors include the battery’s general quality, usage quantity, and storage conditions. Hence, it’s crucial to understand how to inspect your deep cycle battery for any malfunction.

Conduct a thorough visual examination of the battery

Whenever you have a suspicion that your battery is failing, the initial step should be to look for deterioration indicators. This includes inspecting the battery’s surface for any corrosion or fluid accumulation and checking for any signs of loose terminals.

A cracked or loose terminal might become harmful, especially if the battery is utilized for an extended period, as this fault can cause short-circuiting. Other signs you can look out for include any discoloration on the surface and cracks on the battery’s casing.

Use a multimeter for voltage readings

Voltage readings will indicate how much power is being used by the battery. Multimeters can also be used to test for continuity, which indicates a leak in the battery. However, ensure you are aware of your battery’s normal voltage amount. This will help you make comparisons and see whether there are any fluctuations.

These readings are also available on the side of the battery as a reference. Multimeter readings such as zero volts are indications of short-circuiting, while a 12-volt deep cycle battery that remains below 10.5 volts even after hours of charging might be a sign of a dead cell.

Perform a load test

Load testing is the most accurate way to tell the condition of a deep cycle battery. It involves disconnecting the battery’s terminals and connecting a load tester, which will compare the test load with the minimum passing voltage. This device is available at most auto spare shops or hardware stores. Alternatively, you can also pay a fee at any automotive shop where they will test the battery and let you know its condition.