Apple's Tim Cook had a lot to say about the Apple Watch at the Sept. 9 event where it was revealed, but one thing that was strangely missing from the presentation was the device's battery life.

While the company's CEO mentioned that the device would be able to be "worn all day, for any occasion," many are wondering what this means exactly, and how Apple defines "all day."

Even Apple itself is reportedly disappointed with the device's battery life and has declined comment on the issue.

When asked why he skipped over the topic of battery life at the keynote speech, Cook denied having skipped the issue.

"I don't think we skipped over it. I addressed it in the presentation myself," Cook said in a post keynote interview. "We think that based on our experience of wearing these, that the usage of them will be really significant throughout the day. So we think you'll want to charge them every night, similar to what a lot of people do with their phone."

In other words, it seems as though the battery life of the device will be less than a day. This is fine for those who only need it for a day at a time, but it does pose a problem for the occasional camping trip or when the power goes out.

Despite the question of battery life, many are hailing the device as Apple's next big thing. The real test will be whether or not the company can replicate the success that it had with the iPod, iPhone and the iPad. When the iPad was first released, many were skeptical about its use and whether or not it would take off.

"It is the next chapter in Apple's history," Cook said at the event unveiling the device. "It will redefine what people expect from a watch."

The Apple Watch has a big selling point in the fact that it is extremely customizable, putting it ahead many other smart watches. Users will be able to personalize the device with different colors, materials and so on.

Because of this and the fact that it is an Apple product, many are saying that the device could pose a big threat for the Swiss watch market.

As is often the case with Apple products, a premium product like the Apple Watch comes at a premium price. The device will cost $349 or more when it is finally released to the public in 2015.