ThinkPad T series T420s, and the T520, have been lauded for their battery life – up to 30 hours with a 9-cell battery slice. ThinkPad T series The ThinkPad T series is a line of laptop computers introduced by IBM in 2000. After the transfer of the consumer computer division in 2005, they were developed and marketed by Chinese technology company Lenovo. IBM introduced the T series as part of their ThinkPad brand in 2000. The laptop was meant to cater to users working with multiple networks and in different environments. This resulted in the development of the IBM Embedded Security Subsystem. From
ThinkPad L series ThinkPad L series The ThinkPad L-series laptops from Lenovo were designed with the theme of "green". The first laptops in the series were described by Lenovo as being the environmentally friendliest products in the ThinkPad range. Key features that contributed to the eco-friendly tag were the use of recycled material for packaging and post-consumer recycled content (such as office water jugs and used IT equipment). The predecessor of the ThinkPad L series was the ThinkPad A series, conceived as a desktop replacement. The ThinkPad A series was discontinued in favor of two product lines, the ThinkPad R series and the