Power supply systems and methods are provided. In one aspect, a power supply system includes a frame, a power input to receive input power from a power source, a power output to provide output power to a load, at least one battery module mounted in the frame and having a battery output that provides...http://www.google.co.uk/patents/US20080157601?utm_source=gb-gplus-sharePatent US20080157601 - METHODS AND APPARATUS FOR PROVIDING UNINTERRUPTIBLE POWER
