Lenovo ThinkPad T420si (English) User Guide - Page 33

• Integrated WiMAX (on some models) Security features • Fingerprint reader (on some models) Specifications Size • Width: 343.0 mm (13.5 inch) • Depth: 230.0 mm (9.05 inch) • Height: 21.2 to 26.0mm (0.83 inch to 1.02 inch) Environment: • Maximum altitude without pressurization: 3048 m (10,000 ft) • Temperature - At altitudes up to 2438 m (8000 ft) - Operating: 5.0° C to 35.0° C (41° F to 95° F) - Storage: 5.0° C to 43.0° C (41° F to 109° F) - At altitudes above 2438 m (8000 ft) Maximum temperature when operating under the unpressurized condition: 31.3° C (88° F) Note: When you charge the battery pack, its temperature must be at least 10°C (50° F). • Relative humidity: - Operating: 8% to 80% - Storage: 5% to 95% Heat output • 65 W (222 Btu/hr) maximum, 90 W (307 Btu/hr) maximum, or 170 W (580 Btu/hr) maximum (depending on the model) Power source (ac power adapter) • Sine-wave input at 50 to 60 Hz • Input rating of the ac power adapter: 100 to 240 V AC, 50 to 60 Hz Battery pack • Lithium-ion (Li-Ion) battery pack Battery life • For percentage of remaining battery power, see the Power Manager Battery Gauge in the task bar. • The Power Manager also displays a green, yellow and red indication. A battery under warranty with a red indication is eligible for a warranty replacement. Operating environment This section provides information about your computer operating environment. Chapter 1. Product overview 17