Laptop batteries are the remote power source for all types of laptop computers. They are what make laptops so mobile. Though laptops can be used without a battery, they are not nearly as convenient and lose a substantial amount of effectiveness. Laptop batteries have evolved over the years to become much more functional and durable than their predecessors.

In most cases, modern laptop batteries are lithium-ion batteries. They have good power to weight ratios and are more durable than many other types of rechargeable batteries. Laptop batteries made from lithium-ion also have no memory effect, meaning they do not need to be fully charged in order to have a full charge the next time.