Batteries are reliable so far Havent had them too long but I have used several of the tools and they last considerably well. I like the lights showing strength of battery. Helps keep u on track knowing how long the battery will last
As far as quality goes, the Skil lithium battery is second to none in my opinion. The usb port for charging may be great for some, but it is an option that I will not use, but some may find that it is a useful option to have.