It is easy to do if you buy the kit - they come with the battery, o ring and hatch for most models. It is as simple as giving it a twist, poping in the new bat and o ring, and another twist and its installed.
When traveling, I always carry an extra battery kit. Battery life varies greatly depending on the features you use. The
compass and the backlight use the most power, so the more you use them, the quicker the battery will go.
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 | Compass |  | Compasses are sensitive, absolutely crucial instruments to precision navigation. The earth's magnetic field, inclination, and your longitude and latitude all influence the horizontal plane of a compass needle. As a result, compasses are balanced for different geographical zones. Suunto Compasses overcome this limitation to traditional compasses by using a simple 'Two Zone System'. With a Suunto Compass, the only 'balancing zones' are the northern and southern hemispheres. In addition to this innovation, certain Suunto Compasses come equipped with useful features like luminous needles and marks, centimeter/inch scales, magnifying glasses, clinometers, sighting notches, and more. | |  |
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