Power tool batteries are expensive. But, right now, The Home Depot will give you a free battery when you buy specific Milwaukee M18 battery-powered tool. This 2 Ah battery is extremely compact and works with all the tools across the M18 lineup. Every tool kit needs a drill and a driver. Combined with the extra free battery, this is a great way to dive into the Milwaukee battery system or refresh your arsenal of batteries if you’re already a dedicated user.