How does primary and secondary battery work for a laptop?

* Primary Battery - energy is exhausted when active materials are consumed (carbon-zinc dry cell, lithium battery, silver oxide battery, alkaline battery) * Secondary Battery- active materials are regenerated by charging (nickel cadmium (NiCd), nickel metal hydride (NiMH), Lithium Ion, Lithium Polymer, Sealed Lead Acid. Consumer market put aside, the largest users of primary (non-rechargeable) batteries are the military, specialty emergency services and forest fire fighters. High energy density, long storage and operational readiness are among their strong attributes. No charging and priming is required before use. Logistic is simple and battery power can be made available at remote locations that are unmanned and have no electrical power. Disposal is easy because most primary cells contain little toxic materials.

Primary batteries have the highest energy density. Although the secondary (rechargeable) batteries have improved, a regular household alkaline provides 50% more power than lithium-ion, one of the highest energy-dense secondary batteries. The primary lithium battery used in cameras holds more than three times the energy of a lithium-ion battery of same size.