READ FIRST
Throughout this article I will be telling you all about the various batteries that various people should have. I am not telling you to go out and spend thousands of dollars on extra batteries. There are cheaper batteries out there that work just as well. I have 4 batteries for my camera, a Canon EOS 10D, and I only spent about $70-80. So do not go out and spend fifty dollars on a single battery, because there are places that have them for less.

Backup Batteries

For the business person

For any businessman or woman it is essential to be reachable at all points. Whether it is email or cell phone, a business person is expected to be able to be reached at all times. For those of us that cannot charge our phones or laptops all the time it is nice to have a spare battery just in case. I like to keep at least one fully charged battery at all times, so that if the battery in my cell phone or laptop dies completely, I can put the fully charged one in, while the dead one gets a chance to charge. I have a Smartphone, so I can get my email on the go. The only problem is that that takes a lot of battery power. So it is nice to have a spare so that when I need my battery I can use it.

For the photographer

As a photographer I know how important batteries are. For those of us that use a battery grip, it is especially important. The battery grip, as many of the photographers know, uses two batteries. It is not a necessity to have a battery grip, but it is a nice feature. However, this means that you use double the battery to keep the camera going. I have four batteries, as I said before, and I use them all the time. It is nice that no matter what I can have two batteries in my battery grip, and I always have two fully charged ones in my bag. These extra batteries are as important, if not more important, than extra memory cards.

For the student

Don’t you hate it when your batteries die? Dead batteries are a pain, whether it is for your laptop, cell phone, iPod, Gameboy, speakers, or even your flashlight. All of these things have backup batteries. As far as the things that are taking AA/AAA or anything other kind of battery like that, I would recommend rechargeable batteries. They cost roughly the same amount as regular batteries and they have the added benefit of being reusable. If you buy a charger, they usually come with about 4 batteries that work in that charger. This means that you get the charger and four batteries, all of which can be used over and over. Similarly, you can buy extra cell phone batteries and iPod chargers. Some of the iPod chargers are portable, even some that look like cases, but charge the battery at the same time.