Which of the following is the most common laptop battery found today?

Nickel-Metal Hydride (NiMH) batteries were common in older laptops but have been largely superseded by Lithium-Ion due to Li-ion's superior energy density and performance.

Lithium-Ion (Li-ion) batteries are the prevailing choice for modern laptops and portable electronics because they offer a high energy density, a long cycle life, and do not suffer from the 'memory effect' seen in older battery technologies.

Energizer is a brand name for batteries and does not represent a specific battery chemistry type.

Nickel-Cadmium (NiCad) batteries are an older technology with lower energy density and a significant memory effect, making them largely obsolete for modern laptops.