They also come in the form of straps, with solar cells on the outer surface and a nickel metal hydride battery within. Current solar cell technology limit the effectiveness and practicality of phone solar chargers for everyday use. Phone charge times vary depending on the battery capacity installed which continues to increase, further extending the charge times of solar chargers. The fold-out design has proven to allow for higher charge current while maintaining a compact size and current designs are capable of charging a modern smartphone in 3 hours.
Employers that have personnel driving company owned vehicles during the course of business could be held liable if an employee is involved in a accident while using a cell-phone. Implementing a mobile phone policy and creating a general vehicle use policy is the first step to reducing employer liability. Although a mobile phone and a hands-free policy doesn't completely remove the employer from being held responsible for accidents or injuries that could occur while using a company owned vehicle, it does show some forethought and responsibility on behalf of the employer and may mitigate damages.