The Tadiran SL 2780 D size battery is an industrial-grade battery for the best quality in an emergency power supply. With an energy density of 3.2 watt-hours per kilogram, this battery is the most energy-dense battery in its class. It also has a high discharge rate and is highly resistant to vibration and shock. The SL 2780 D size battery is compatible with a wide range of applications, from aviation to automotive, and even marine. This battery can be used in a wide range of applications and is a powerful, reliable option for any emergency power supply.