Batteries are supposedly lasting longer. But – if they are – I haven't noticed much of an improvement.

The battery in my mouse still runs out every three weeks. In my remote control device, every month.

In my car, every two to three years, same as a couple of decades ago.

I've stopped buying flashlights. On the rare occasions I took them out of storage during power outages, they didn't work. So why bother?

Batteries stunk 30 years ago. They still do.

The technology is overdue for a major overhaul.

Of course, you could have said the same thing 20 years ago.

Yet the industry is littered with failed battery startups over the years.

One of the bigger ones is A123 Systems. It made lithium-ion batteries for vehicles and the electric grid.

A123 Systems had one of the biggest IPOs of 2009. But the market for electric vehicles grew more slowly than expected. The company was forced into bankruptcy and its assets eventually sold off.

Technology runs in cycles. The Internet technology that drove the dot-com industry over the cliff at the turn of the century wasn't quite ready yet. It needed to mature. Once it did, it gave rise to dozens of large and profitable companies.

President Carter tried to launch a clean tech revolution but, again, the technology wasn't ready. But now – decades later – we're seeing some pretty amazing things.

Just this week, for example, Tesla (TSLA) announced that its cars will be able to go 620 miles on one charge within the next year or two.

So, where are we in the battery technology cycle?

I believe we're entering the stage where big, game-changing improvements take place.

The technology is ready. And the marketplace is primed.

The best example of what's going on?

Look at what Elon Musk is doing.

A Tesla for Everybody?

Tesla cars are a triumph of vision and technology. Of course, they're a high-end luxury product. Tesla sold 17,300 of its cool cars in 2014 and 14,500 so far this year (through August).