PAT testing means Portable Appliance Testing, which basically means testing anything that plugs into an electrical socket, either directly or for charging. It's a legal requirement that all workplace electrical items should be safe to use, and PAT testing is a relatively inexpensive way of ensuring safety. Any Health and Safety audit or inspection will expect to see evidence that electrical safety is being taken care of seriously. Have your equipment tested in a competent manner and ensure you have the paperwork to back up your strategy.