A car battery is one of the most important components in the engine. Without it, the vehicle can’t start. But how long do car batteries last—and how do you know when it’s time to replace it?
There are several styles of battery in use in today’s vehicles, and they don’t all last for the same amount of time. Environmental conditions and how you drive your car can also affect a battery’s overall lifespan.
Let’s look at all the factors that affect the life of a car battery. This info will help you to better predict the life of your battery.
The Reasons To Know How Long Car Batteries Last
If you’ve ever drained your battery and found yourself stranded, you understand the importance of knowing your battery’s lifespan. Knowing when your battery will die lets you be prepared. Even if you don’t instantly replace the battery, you can have a new one waiting in the trunk, just in case.
How Long Do Car Batteries Last?
This depends on a lot of factors, including your driving style, the conditions where you live, and the style of battery. If you’re wondering “How long do car batteries usually last?”, the short answer is 5-7 years on average.
Heat and moisture are a battery’s main enemies. High temperatures cause the battery’s internal components to degrade, reducing its maximum capacity over time. Humidity, meanwhile, can lead to corrosion, which reduces a battery’s efficiency. If you live in a particularly hot and humid climate, your average car battery life may drop to 3-5 years.
Sitting unused for long stretches of time will also lower a battery’s maximum lifespan. The best way to maintain a battery is to keep it fully charged all the time. Your vehicle’s engine keeps the battery charged while you’re driving. When it sits, though, it slowly drains.
To get the most out of your car’s battery, you should drive it at least every other day. If it’s a car that’s used very infrequently (twice a month or less), consider getting a battery maintainer. These devices provide a steady, low-level charge, topping off the battery any time its charge drops too low.
Finally, the type of battery you own affects the maximum lifespan. For traditional vehicles, there are two main battery styles: standard lead-acid and AGM (absorbed glass mat), a more durable version of the lead-acid design. AGM batteries last a bit longer on average—usually around 6-8 years, in ideal conditions.
How Long Do Hybrid Car Batteries Last?
Hybrid and electric vehicles use a different style of battery than standard combustion engines. Some hybrids use traditional lead-acid or AGM batteries. Others use NiMH batteries (nickel-metal hydride) or Lithium-ion batteries.
So how long do hybrid car batteries last? NiMH batteries have the shortest lifespan, at 2-3 years. Lead-acid or AGM batteries will have the same expected lifespan as in a traditional vehicle. The longest-lasting batteries are lithium-ion, which has an average lifespan of 8-9 years.
How Long Do Electric Car Batteries Last?
You’re probably also wondering how long do electric car batteries last. Just like with hybrids, not every electric car uses the same style. Along with the lead-acid, NiMH, and Lithium-ion options above, some electric cars use ultracapacitors.
Ultracapacitors use a polarized liquid to store energy. They’re not batteries in a traditional sense, but they serve the same function as a lead-acid battery in the car’s engine: storing power. They also have the potential to last as long as 15 years before needing to be replaced. Most ultracapacitors in cars last 5-10 years, on average.
Step-by-step guide: How to read battery date code
You likely don’t remember exactly when you installed your last battery—and if it’s a new car, the battery might or might not be the same age as the vehicle.
The good news is, batteries are stamped with a date code. Reading this will tell you exactly how old the battery is. Let’s break it down step by step:
- Locate the date code. This will typically be engraved or stamped into the battery cover, usually at or near one of the corners. In some cases, it will be directly on one of the terminals. It will be a series of 1-2 letters and/or 1-6 numbers. The exact configuration depends on the manufacturer and the style of the battery.
- If there is a letter from A-L, this tells you the date of the battery’s manufacturer. An “A” indicates the battery was made in January, a “B” stands for February, and so on. If there’s a second letter, it will usually come from the end of the alphabet. This indicates the plant of origin. Consult the manufacturer’s website to learn more.
- In codes with 1-2 numbers, this indicates the year. A single number is the last digit of the year it was manufactured. A 9 means 2019, an 8 means 2018, and so on. If there are 2 numbers, they will be the last two digits of the manufacturing year (e.g. 19 would be 2019).
- In date codes that consist of 5-6 digits, the numbers translate to the date of manufacture. Most 6 digit codes read DDMMYY format, so 010119 would be January 1, 2019. A 5-digit code normally takes an MMDDY format. January 1, 2019, would be expressed 01019.
If you’re having trouble finding or interpreting the date code on your battery, find the manufacturer. Most have specific instructions for their batteries available online.
While it’s impossible to know exactly when your battery will die, the date stamp can help you get a rough idea. Use the tips above to get the most use out of your battery life. Hopefully, we’ve answered all your car battery life questions! You can also see how your car battery works here!