Buying guides

• Choosing a power bank: what mAh really means What the mAh figure on a power bank tells you, why you never get all of it, and how to pick a size for your phone, tablet or laptop.
• Choosing a security camera: what to look for The features that matter in a home security camera: resolution, night vision, storage, power and where to put it.
• Choosing power tools: corded or cordless, and what the numbers mean How to decide between corded and cordless tools, and how to read volts, amp-hours, watts and speed on the box.