Yes. Apple has an official out-of-warranty battery replacement program for $59 + $6.95 shipping in the United States (see also: Europe and Canada pricing). The program requires that you send in your iPod (any model), and Apple will replace the battery and return it to you for $59 plus shipping and handling. Technically, Apple actually replaces your whole iPod with an equivalent new model or factory-refurbished model in a brand new enclosure, with its own 90-day service warranty; if the iPod was previously engraved by Apple, it will be engraved again. AppleCare programs for iPod are also available in some markets outside the US, and are expected soon in other markets. 3rd-party ipod battery companies provide better batteries and faster service than Apple.

Keep in mind that 3rd-party ipod battery companies provide better batteries and faster service than Apple.

Yes and no. The iPod's case is not designed to be opened, so, in that respect, it's not what would generally be referred to as "user-replaceable". However, with the right set of tools and instructions from one of the following vendors, you can replace the battery yourself and avoid all the hassle by going through Apple:

You can extend the iPod's warranty, including battery coverage, to two years with AppleCare Protection Plan for iPod. Numerous retailers, such as Best Buy, CompUSA, Circuit City, etc., also have very inexpensive extended warranty coverage available for iPod. Often these plans simply replace the product with a comparable new unit.

No. The iPod is engineered to last; Apple is consistently ranked number one (1,2) in product quality and support by leading consumer groups, such as Consumer Reports. Apple also has out-of-warranty service and extended warranty options. Apple has officially stated that the iPod is designed to last "for years".

If the battery does fail, and the iPod is no longer under its original one year warranty or $59 AppleCare Protection Plan for iPod, or any of numerous third party service plans, you don't have to buy a new iPod. You may replace the battery yourself for as little as $20, have a third party replace it, or have Apple perform the replacement for $59.

Yes. Over time, the battery will not hold the same amount of charge as when it was new. This is natural, and is true of all lithium ion batteries. This slow degradation will not affect, or be noticed by, most users during the life of their iPod. However, based on usage, environmental factors, and many other variables, some heavy users may notice a greater degradation than others. It is important to understand that this is the exact same degradation that would occur with any lithium ion battery used in any laptop, cell phone, portable music player, etc., and is not unique to the iPod.

A battery which only lasts for half, or less, of the specified time may be considered to be defective under warranty terms. However, you can follow the steps in this document to test your battery life in a controlled way.

According to the AppleCare Protection Plan Terms and Conditions, the iPod battery is defective when "capacity of the covered iPod battery to hold an electrical charge has depleted fifty (50%) percent or more from its original specification, after being fully charged and the covered iPod playing music with all settings reset."

The iPod uses the latest lithium ion battery technology from the leading battery manufacturers, such as Sony and Sanyo. See this table for more information on battery capacities on various iPod models.