How long is the battery life of an AvaTrace M60?

Temperatures above freezing: 4-5 months.
Temperatures below freezing: 3-4 months.

When measuring with one accelerometer the battery life time is reduced to 75 % of the given values above.
When measuring with two accelerometers the battery life time is reduced to 50 % of the given values above.
When measuring with more than 2 accelerometers the battery life time is reduced to 30 % of the given values above.