Dell laptop battery does generally come with different specifications ranging from type, voltage and the number of cells. It is always recommended that the battery you buy specifically matches your Dell laptop. It also should match your needs. If you are a heavy user it is advised that you buy a battery with more cells so that it can run for a long time. Some Dell laptops like Inspiron and XPS do have an inbuilt battery due to the sleek nature of such laptop. It is also wise to know that the rechargeable Dell laptop battery does degrade after a period of time. This means that it must be replaced when it drops charging quickly. Make sure to use the correct adapter for your Dell laptop.