How come car batteries don't last like they used to?

Car batteries. They don't make them like they used to.

Well, actually they do, and that's the problem.

Still clinging basically to the electrical technology of the 1960s, car batteries now are asked to fill a lot more demands. Batteries are called on to power navigational and security systems, cell phones and iPods.

The result? The average life of a battery used to be about 37 months. Now, according to experts, they fizzle at 24 months.

Add to that the long hot summer in Florida. Heat, the experts say, is not good for batteries.

AAA roadside service says there are a lot more calls for dead batteries than there used to be.

Since 2000, requests across the nation for battery assistance went from about 4,000 a year to more than 400,000.

AAA roadside service workers expect to be out this holiday weekend answering calls for dead batteries too. According to their records, jump start and battery replacement calls over the holiday weekend last year increased by 41 percent over the year before.

In 2008, AAA service technicians responded to 3,655 Florida motorists with battery problems throughout the Labor Day weekend compared to the 5,138 motorists who needed help in 2009.

But it's more the mechanical and electrical demands on batteries that drain them, said Jay Bolster, senior manager with AAA Battery Service Operations.

"We want motorists to be prepared if their battery fails this Labor Day weekend," he said. "It's a busy holiday for motorists and extremely hot - the heat alone can drain a battery."

Cars today require a lot of juice, he said, and batteries have not changed much over the years.

"Basically, it's still a black box," he said. "With cars the way they are nowadays, with internal computers, there's a higher demand on batteries."

Even though devices like cell phones and iPods don't charge when the battery is off, there always is a drain somewhere in the car, he said.

"We call it parasitic drain," Bolster said. "Even as your car sits in the garage overnight with the engine off, there is a lot of drain, things like the memory presets on your radio. That requires juice."

There is constantly research and development on car batteries, he said. Mostly scientists try out different internal materials from silver to lead to glass. But batteries still retain the same design they had since they first started providing juice to start the car and power the headlights.

It wasn't that long ago when car batteries were used only to light headlights at night and power the starter when the key is turned. Now, Bolster said, they are called upon to charge cell phones, laptop computers, iPods; navigation and alarm systems. There are power fans, diagnostic systems and engine management tools, all of which require power even when the car is turned off.

There shouldn't really be an excuse for being stranded with a dead battery, car experts say. Dying batteries always give clues about what's going to happen.

The car typically will start slower than usual and interior lights may dim or flicker.

When that happens, it's time to test the battery to see if it needs to be charged or replaced.

When batteries go kaput, turning the key results in a series of rapid clicks.

Dave Pressel, the battery expert at Batteries Plus in north Tampa, said heat is more of a drain on batteries than electronics.

"Heat is tough on batteries," he said. "Batteries in this southern climate don't last as long as batteries up north."

Even though electronics in cars are more and more demanding, said Pressel, who has been with the battery store for 13 years, "batteries seem to be doing well."

While battery manufacturers are researching the development of long-lasting expensive batteries to power hybrid and electric cars, batteries designed for gasoline-powered vehicles aren't changing that much.

Since 1800, batteries basically have created power the same way. That's because a battery's power comes from a simple chemical reaction. Materials inside the cell may be fiddled with, but the fundamentals of the chemical reaction remain the same.