Can I use a battery from another system in my new laptop if it fits?
Can I use a generic battery in my laptop?

Li-Ion cells are permanently damaged when their charge drops below certain levels. If the voltage gets too low, the battery will stop working and become unsafe to use. Therefore all systems powered by Li-Ion batteries have a predefined threshold set to shut down at certain levels of discharge. As a result, Li-Ion batteries are made to the exact specifications of the systems they are designed for, and vice-versa. This is where batteries from another system or low-cost generic batteries may not be compatible. If the thresholds of the system and battery do not match, there is a risk of power cutting off at the wrong moment. This may lead to unsaved work being lost, data corruption, or irreversible battery damage.

In addition, generic low-cost batteries are not made with the high safety standards of official batteries. Main-brand batteries use only approved safety circuits in their battery packs whereas there is no regulation of off-brand battery production. This, as well as attempts by notebook manufacturers to ensure approved batteries are used, is responsible for the higher cost of official batteries. There have been reports of notebooks rejecting generic batteries (to avoid usage of potentially dangerous batteries) without software changes (bypassing the security system). Some generic batteries even fail to work altogether.

There are subtle differences in design, manufacture, and the operation of generic and official batteries which may or may not cause problems for you. For every person that has had problems using generic batteries, there is another who has had no problems whatsoever. You must decide if saving a little money on a replacement battery is worth the potential risks.