Determining when you need to replace your battery can be really simple. One of the easiest (and most frustrating) ways is if your car won’t start and when you attempt to re-charge it, the battery won’t hold a charge. This makes it pretty obvious that you need a new battery.
The next most reliable way is if you find that you are having difficulty starting your vehicle in the morning. This usually happens more frequently in the winter, but hot climates can also shorten battery life. If your vehicle starter is sounding more sluggish, it might just be time for a new battery.
Although these symptoms suggest a failing battery, they are not conclusive. It is possible that the connections have become corroded over time and just need to be cleaned or it might be that one of the two battery cables has come loose or needs replacement. You might have a short in the electrical system that is draining power overnight. It is also possible that the alternator is not re-charging the battery as it should.
Batteries do not last forever, the average for factory-installed, original equipment is 8 years. While many people can replace their own battery, they do weigh around 20 pounds and are filled with acid. Batteries come in various sizes (both physical and in ‘cranking power’) and it is important to replace it with one sized appropriately for your vehicle.
So, even if the battery is well past its expiration date, its wise to have the cables and charging system checked out at the same time. That way, you won’t find your self with another dead battery in a week or less after replacing it.