Fully charged Styletto hearing aids provide an: up to 19 hours daily runtime without streaming; and up to 16 hours daily runtime with 5 hours direct streaming. The runtime of all lithium-ion rechargeable batteries reduces over time. The estimates are based on fresh lithium-ion rechargeable battery capacity. Under normal operating conditions, the battery will retain up to 80% of its initial capacity after 2 years of use. Please note that battery performance will vary depending on individual usage patterns and environmental conditions.