iPod external battery packs are basically a backup battery for the Ipod. They are basically batteries that can plug into an iPod. These work in the same basic way that your USB charger works. They charge your iPod so that you continue to use it. There are a few different types. There are the ones that plug in and have a separate battery pack.
For example, you plug the Ipod into the battery pack and they are two completely separate things that are connected by a wire. Then there are the “case” battery packs. These ones are the most highly recommended. The reason for this is that they are not only a battery pack but also a case for the iPod. Most of them have a little power button, or slider, so that you can allow the battery to completely die before going to your backup. These seem to be the most practical.
Why spend the money?
iPod external battery packs can be a little more expensive than they seem to be worth. However, having a battery pack will extend the life of your actual iPod battery. The reason for this is that you should not charge your iPod, or any other rechargeable device, until the battery has fully died. The reason for this is that the battery becomes weaker if it is charged before it has died. That having been said, these battery packs act as an emergency battery. If you are going to be out all day with no car or home to charge your iPod you will want a battery pack. For example, if you are about to go to sleep and you realize that your battery has little battery left; you may want to charge it. However, this will make the battery weaker. Now, with an external battery pack, you do not need to worry because even if your iPod dies, you are able to charge it back up, no matter where you are.
Which one to buy?
Personally I would recommend a “case” battery pack. This is because it is less likely that you will lose a battery pack that is directly attached to your iPod. That having been said some people might enjoy a separate battery pack. The reason I would personally recommend “case” battery packs is that I am on the go a lot. When I am out I want that extra battery to be right there; not two separate things that I have to keep track of. This is especially helpful for those of us that travel. The one that I have is a case that holds my iPhone and has a little leather flap for screen protection. It is perfect because I was looking for a case, and I was looking for a battery pack, and for fairly cheap I got both in one.
Is it really necessary to have a battery pack? Is it an absolute necessity to have a battery pack? Not necessarily. However, I would say that if you travel a lot or if you are a business person whose life is on their iPhone I would say yes. The reason is simply that these will help preserve your iPod/iPhone so that you can truly get the most out of it. Furthermore, I would more highly recommend a battery pack than most other accessories.