One big reason I like the new Leica Line of Rugby Laser, the a rugby 600 and the rugby 800 is they give you good options for powering the lasers.  Both the Leica 600 and 800 series allow you to use either alkaline batteries or lithium (Li-ion) batteries.  So what's the big difference between the two?

Alkaline batteries are very convenient.  Less up-front cost and they never require charging.  Many contractors love this type of battery.  But when you consider the average laser is 10 or were years old, that's a lot of batteries to buy.  Also, they can make a mess in your laser if you leave them in for a extended period of time with no use.

Lithium Ion (Li-Ion) batteries can be charged up will either a 110 volt wall charger or a 12 volt auto charger.  The Lithium Ion batteries do not have any memory problems and can last for many years.  A much cheaper way to go in the long run versus alkaline batteries.

I recommend to all my contractors, that when they purchase either a Leica Rugby 600 or 800 laser they get the lithium ion battery pack and get the alkaline pack as a back-up.  Then they are never down.