System and Screen Size
The DSi XL is appropriately named because it features an extra-large screen. The DSi XL screens have 93 percent more space than the screens found on the original DS and DS Lite. The larger screens mean that the DSi XL is a substantially larger device than the DS Lite--which can conveniently fit in a pants pocket. The original DS model's total size is between the Lite and DSi XL's. The DSi XL also weighs about 50 percent more than the DS Lite. However, both devices are very light, as the DS Lite is under half a pound and the DSi XL is just over half a pound.
Camera
The Nintendo DSi added front-facing and back-facing cameras to the Nintendo DS Lite hardware. The DSi XL retains the camera features. The Nintendo DS and DS Lite models do not have built-in cameras. These cameras can be used by augmented reality games and by the DSi's built-in software. The cameras will not make a difference to someone playing DS games that are not specifically designed to use the camera.
Downloadable Games
The DSi XL is able to download games from Nintendo's online game store, while the DS and DS Lite are not. These games are stored on the DSi XL's internal memory, another feature neither of the older DS models has.
Backwards Compatibility
While the original DS and DS Lite are not able to play downloadable online games, they are capable of playing games for Nintendo's previous handheld device, the GameBoy Advance. The original DS can play games from the original GameBoy as well. The DSi XL does not feature a cartridge slot for GameBoy games, so it is unable to play them.
Battery Life
The original Nintendo DS features abysmal battery life in comparison to the other Nintendo DS models, topping out at 10 hours of use per charge. The DS Life is able to get 15 to 19 hours of game play on a single battery charge when using the lowest back light setting. This number decreases when using brighter back light settings. The original DS can only toggle the back light and cannot adjust it, which partially contributes to the poor battery life. The DSi XL can get between 13 and 17 hours of use with the lowest back light setting on a single charge. While the DSi XL is a larger device and uses more electricity to run, it includes a higher-capacity battery to balance things out.