The short answer
Across the country, a car battery usually lasts somewhere between three and five years. In the Dallas–Fort Worth area, plan on the short end of that range. A battery that gives out in its third or fourth summer here is not unusual, and one that reaches five has had an easy life.
That is a general figure, not a promise. A well-made battery that lives in a garage and gets driven every day can outlast it. One that sits in an open lot all summer, in a car used only for short errands, can fall well short.
What heat does inside the battery
A battery makes electricity through a chemical reaction between lead plates and acid. Heat speeds that reaction up, including the slow side reactions that eat away at the plates. It also drives water out of the acid in batteries that aren't fully sealed. None of that wear can be undone.
Under the hood it is worse than the weather report suggests. The battery sits close to an engine that was just running, so on a 100-degree afternoon it is a good deal hotter than the air around the car. Summer does the wearing. The first cold morning is when it shows.
What shortens it, and what stretches it
Heat sets the pace, but a few other things move the number up or down:
- Short trips. Starting the engine takes a lot out of the battery, and a ten-minute drive may not put it back.
- Where the car is parked. A garage or shade keeps the battery cooler than an open lot.
- Hardwired accessories. A dash cam or an alarm keeps drawing a little power while the car sits.
- A loose hold-down. A battery that can move around in its tray takes damage from vibration.
- Weeks of not driving. A car that goes unused lets the battery drain down over time.
How to find out how old yours is
Most batteries carry a date code, either on a sticker or stamped into the case or a post. The format depends on the maker. Often a letter stands for the month and a number for the year, but not every brand does it that way. If the code doesn't make sense to you, the receipt or the shop that installed it will have the date.
Once a battery is past three years, treat a slow start as a warning, not a quirk of the car. That holds even if the car starts every single day. A battery near the end of its life can hide it right up until the weather changes.
When to replace it
The easy time to replace a battery is before it fails. If it is turning over slowly, or it is four years old heading into another summer, pick a day that suits you instead of waiting for it to pick one for you.
We replace batteries where the car is parked. Battery replacement is $239–$255 for eligible vehicles and batteries, with the new battery and the installation included, plus the $19 dispatch fee charged once per job. Dispatch confirms the battery that fits your car, and your total, before a driver is sent.
Common questions
It helps. A garage keeps the battery out of the afternoon sun, so it runs cooler and wears more slowly. It won't make a battery last forever, but it is one of the few things within a driver's control.
Keep the terminals clean, make sure the hold-down is tight, and take a longer drive now and then instead of only short hops. Don't leave lights or chargers running with the engine off.
You don't have to, but in DFW heat that is the age where batteries tend to fail without much notice. If you depend on the car every day, replacing it before the next summer is a reasonable call.