These work straight from the box, once you remove the plastic disc in the tail-cap that effectively disconnects the supplied Lithium cells. Very nicely machined and finished. The light is incredibly bright on full power, illuminating my entire 1/4 acre garden very well, it's good on half power and absolutely fine on 1/4 power, which gives considerably greater battery life. I'd be impressed with 1/4 power if that was all these could do! The quality of the light is excellent - perfect, diffuse pools of even daylight white with good colour rendition. The beam adjustment covers a good range, but they're so bright that the number of times I'm likely to need the zoom function to see things further away is small. Includes charger that plugs into any USB power supply. Fantastic value.