The white light beam is more than bright enough, and more importantly the red beam is powerful enough to easily read a star chart in very low light conditions.
As stated the torch comes with a free battery, it takes standard 9 volt batteries. The reason for the inclusion is that there is no quick battery access pannel. You will need to open up the torch to replace the battery. The screws are all very small phillips heads, that are quite deeply sunken into the torch. So you will need a very small yet long screw driver to get it open, a jewelers screwdriver would be recomended for this. I would not recomend trying to change batteries in the field.
Over all this is a good torch that should have a 5 star rating, but the difficulty of replacing the battery is the one flaw that lets down this product. If you can cope with the battery problem then it seems like a good buy.