Lithium-ion (Li-ion) batteries are very stable and reliable sources of power for two-way radios, laptops and many other devices. Lithium-ion batteries are widely used because they have a high energy density, resulting in a much lighter weight than other rechargeable batteries. Li-ion have other advantages too. They hold their charge well, losing about 5% of their charge per month as compared to ~20% for nickel-metal hydride (NiMH) batteries. Li-ion batteries have no “memory effect,” which means recharging them before they are completely discharged is not an issue. Li-ion batteries can handle many recharges before the end of their useful life.