Start-stop cars, and a lot of European and luxury cars, need an AGM or EFB battery, not a standard flooded one. We bring the type your car was built for, install it at your car, register it with the car's computer if the car requires that, and check the charging before we leave. AGM replacement is usually $329 to $449 installed.
Why these cars are different
Picture Dale Mabry at 5:15. Light, stop, engine off. The A/C fan, the screen, the lights and two dozen computers run off the battery. Light turns green, the battery restarts the engine. Thirty seconds later, do it again. A standard flooded battery isn't built for that kind of cycling, and it falls apart fast.
AGM batteries hold their electrolyte in glass mats, are sealed, and handle deep, repeated cycling much better. EFB is a beefed-up flooded design used in some lighter start-stop systems. AGM vs. flooded explains it in more detail.
The rules we follow
- AGM out, AGM in. If the car came with AGM, it gets AGM. Every time.
- EFB can go to AGM. That's an upgrade. Going from EFB down to a standard flooded battery is not.
- Never a flooded battery in a start-stop car. It might start the car this week. It won't last, the start-stop will act up, and you'll have warning lights.
Registration
Many of these cars keep track of the battery with a sensor on the negative terminal. As a battery ages, the car charges it differently. Put in a new one without telling the car, and it can keep charging the new battery like it's the worn-out old one. On a lot of BMW, Mini, Mercedes, Audi, VW, Volvo and Land Rover models, and some others with start-stop, registration is part of a proper replacement. For the vehicles our equipment supports, we do it on site. If your car needs something we can't do, we tell you before we start. Registration explained.
The usual signs
The first thing people notice is that start-stop stops working. The engine just keeps idling at lights. That can be the car protecting a weak battery. It can also be the A/C running hard on a 95-degree day, which in Tampa is a lot of days. If start-stop has been off for a couple of weeks in normal weather, get it tested. Start-stop cars explained.
Other signs: a "battery low" or "start-stop unavailable" message, a slower crank first thing in the morning, odd electrical behavior on startup.
Where these batteries live
Under the hood on some. Under the trunk floor on a lot of German cars. Under a seat on others. Trunk and cabin batteries usually have a vent tube that has to be reconnected. We handle all of it, and it's why some of these jobs take closer to an hour.
Where we do the most of these
South Tampa, Westchase, New Tampa, Palm Harbor and East Lake, Trinity, downtown St. Pete. Lots of newer SUVs and European cars, lots of start-stop. But we go everywhere in our service area.
Questions we get about this
Can I put a regular battery in my start-stop car to save money?
No. It won’t hold up to the cycling, the start-stop will misbehave, and it usually fails early. The savings disappear.
Does my car need registration?
Many European and start-stop cars do. Give us the year, make and model and we’ll tell you before we come.
Why does it take longer than a regular battery?
These batteries are often under the trunk floor or a seat, and registration adds a step.