The 800H will give you 4 hours continuous, high performance light output.  The handlamp will operate in extreme temperatures ranging from -40 degrees centigrade to +60 degrees centrigrade and although constructed to withstand tough handling they are light weight units which float beam up.  The luminous lens rim glows in the dark to aid location.  The battery does not suffer from memory effect, it can be charged whenver convenient to you -on the mains or in the car.