NEW YORK — It may no longer be the sexiest gadget on the block, but the Kindle isn’t going away.

Even before Apple’s iPad debuted earlier this year, many wise tech heads began predicting the imminent doom of’s groundbreaking — but far less capable — electronic book reader. Given all the things the iPad can do — Watch videos! Surf the Web! Run apps! — why would anyone still want a non-color device that really has only one function?

The new Kindle, which is now on sale at Amazon and due to show up soon in Best Buy and Staples stores, offers a surprisingly vigorous response. By cutting the price, adding features and shrinking the size of the device, Amazon has defined a niche that is different enough from the pricey, bulkier iPad to suggest that the two of them may continue to coexist, much as paperback books and hardcovers do in the print world.

The analogy to paperbacks works better and better as the Kindle’s price continues to fall. The new one costs $189, down from $259, and features a host of enhancements, including more capacity, better claimed battery life and a new option to buy books over Wi-Fi as well as cellular-phone 3G networks. A Wi-Fi- only version is even cheaper at $139.

Both Kindles retain the 6-inch monochrome E Ink display of the previous model, although with a few tweaks that Amazon says reduce glare and improve clarity. I believe the claims, although I never had a problem with the old display.

The most obvious changes are in the physical package surrounding the screen. Amazon has shaved half an inch off both the height and width of the device, making it 21 percent smaller. At just 8.7 ounces — the iPad is a pound-and-a-half — there’s little risk of wrist fatigue even in extended use.

Navigating the Kindle software is better than it was, though that doesn’t mean it’s very good. Gone from the front of the device — which is now available in graphite gray as well as the previous off-white — is the little joystick you used to navigate through your library and Amazon’s e-bookstore in the previous-generation Kindle. In its place are four directional keys arrayed around a square button.

I don’t miss the joystick, which I found too easy to accidentally engage. But moving around various menu pages and user settings is a laborious process, and it’s taking awhile to train my fingers to understand that the smooth, flat button isn’t a BlackBerry-style trackpad. Sometimes a button is just a button.

Amazon has more than doubled the Kindle’s capacity to 3,500 books, the company says. And it adds that the Kindle can now go as long as a month between battery charges if you turn off the wireless features, which aren’t really needed except when you’re shopping or downloading books or using the improved but still rudimentary Web browser.

Unfortunately, you can’t prove the improved-battery claims by me. Twice, I fully charged the Kindle, used it for several days, then picked it up to find the battery meter had abruptly plunged from almost full to empty. Amazon says it hasn’t had an unusual number of complaints about the battery.

The most important thing for an e-reader, of course, is that it doesn’t get in the way of reading, and here the Kindle shines. Jeff Bezos, Amazon’s chief executive officer, frequently refers to the idea that the Kindle should disappear in the reader’s hands — that the words rather than their container are what’s important. And this model fills the bill admirably.

It’s a mark of how fast things change in the tech world that the Kindle, which was so cool and cutting-edge only a year or two ago, now seems almost prosaic. Still, while the iPad may be the gadget you choose to bring to work in your briefcase, the Kindle’s the one you jam into the gym bag. Its size, price and features should give it a future, even in an iPad world.