The document summarizes and compares the key characteristics of four common rechargeable battery types: lead acid, nickel-cadmium (NiCd), nickel-metal hydride (NiMH), and lithium-ion. It provides a table that rates each battery type on factors like energy density, cycle life, self-discharge rate, voltage, cost, and maintenance needs. Lithium-ion batteries are highlighted as replacing many applications previously using lead or nickel-based batteries due to higher energy density, longer cycle life, and lower maintenance needs reducing the overall cost per cycle compared to other chemistries.