The upper half of the solution is a light acid, while the bottom is a heavy acid.
![car battery car battery](https://cdn.fiix.io/1/car-parts/battery.png)
Inside the battery, the electrolytic solution goes from homogenous - or the same all the way through - to a rough vertical split. This constant state of undercharge results in acid stratification. That means if you have a short commute or take lots of brief trips, the battery never gets fully charged. Starting the car takes a huge jolt of electricity, so the charging system has to step in to replenish the battery. Therefore some batteries are covered by an insulating sleeve to keep extreme temperatures in check.ĭriving style can affect the reaction, too. Extreme heat speeds up the chemical reaction, shortening battery life, while extreme cold can sometimes prolong battery life by slowing down the reaction. Vibrations from rough travel or a poorly-secured battery can shake loose or damage the plates. This solution allows electrons to flow between the plates - that flow of electrons is essentially electricity.Ī host of factors can disturb this chemical reaction. The plates are suspended in a mix of water and sulfuric acid, which forms an electrolytic solution. Inside the plastic box are plates of materials like lead and lead dioxide. If you look at a typical lead-acid maintenance-free car battery, it's easy to make sense of why these factors affect normal battery life. Keep in mind as you read that batteries for hybrid and electric cars are a little different, and this article will primarily discuss batteries for cars with regular gasoline engines. At the four-year mark, start watching for symptoms (which we'll discuss in a bit) and be prepared to take action.īut due to the nature of the chemical cocktail inside any battery, it may give out before you think it's ready, or maybe it will last for several more years.
![car battery car battery](https://i5.walmartimages.com/asr/aa90ccd4-fee3-4fcb-bf7d-76af70cf6272.d733fde0a3ee4b296083f9ff4489d59a.jpeg)
So the rule of thumb is simple for battery replacement: You have approximately four years before the battery will theoretically begin its slide from chemical powerhouse to chemical paperweight. Fortunately, this snapshot will help you keep an eye on the situation. Instead, they provide a sort of snapshot of the battery at the time it's being tested - without the context of the battery's chemical composition before or after the test. Simple battery testers can't, at this time, muddle through the chemical complexity of what goes on in a battery. While the lead-acid car battery hasn't changed much in the last 100 years, testing has gotten a bit easier.