When it comes to maintaining your DLSR camera and making sure that it works properly for years to come, there are always a few important things to keep in mind.
Lithium Ion Batteries
DSLR cameras are most commonly powered by lithium ion batteries, similar to the kind you would find in something like a smartphone or laptop computer. While this is nice because they can be recharged, they do lose their capacity naturally over time. To preserve the battery for as long as possible, try not to charge it until it is fully worn down to around a 10% or so remaining charge. Also make sure that you're not storing that battery in extremely hot or cold temperatures, as doing so will prematurely degrade its lifespan.
The Importance of Software Updates
One thing that many people don't realize is that a DSLR camera actually has a lot more in common with a standard computer than it does with a film camera. DSLRs are digital, meaning that they are powered by computerized hardware and various processor chips in order to capture light accurately and take the best pictures possible at all times. Your camera even has a rudimentary operating system installed, though obviously it isn't quite as advanced as something like Microsoft Windows or Mac OS X.
Because of this, however, one thing that you always need to make sure to do when maintaining your DSLR camera involves downloading and installing any and all software updates as they become available. Doing so serves a few different purposes, all of which are important. For starters, software updates also increase performance and fix certain issues that users may be experiencing. They can also patch certain security vulnerabilities, which is especially important with modern day DSLR cameras that are often connected to the Internet.
Software updates can also add new and useful features, none of which you would have access to if you allowed your device to fall out of date. If your DSLR camera doesn't have a "Software Update" feature built right in, you can normally download and install them from the manufacturer's website using your computer and the same flash-based storage media that you use for keeping photographs.
Cleaning Your DSLR
Try as you might, both your camera and the lens that you're using will eventually get dirty and will need to be cleaned. Doing so always requires you to first power down the camera and separate the lens from the front of the device. Whenever you clean either the lens or the camera itself, always use a microfiber cloth that is soft and clean. When it comes to cleaning your imaging sensor, make sure that you're using a proper cleaning brush to avoid scratching any of the integral components. If you're afraid to do this on your own, don't worry - many local services offer professional cleaning to help your DSLR stay at its best.
Storing Your Camera
Many people pay the appropriate amount of attention to the care of their DSLR when it is in use, but fail to pay the appropriate amount of respect when it's not. Never leave your DSLR in your car, for example, where the temperature can get scorching hot during the summer or freezing cold during the winter. Any extreme temperature will almost certainly permanently damage your DSLR, especially if you leave your camera in these conditions for a long period of time.
Humidity has long been the bane of the existence of photographers all around the world. In the days of film cameras, humidity could ruin a roll of film in a matter of minutes depending on the temperature and the area where the camera is being used. Humidity is just as bad for a DSLR camera, though for entirely different reasons. With a DSLR, water, moisture and humidity don't just threaten the pictures that you're taking - they threaten the entire camera thanks to the complex sensors and other components installed inside.
You need to take care to keep your camera as dry as possible and as far away from extreme weather conditions as you can. Many accessories manufacturers make cases and other storage devices that will help with this issue greatly.