Hallo Jerson,

some time ago I was involved in a data logging project, which monitored serious data of a pipeline, far far away from any 'cicilization'. Circuitry was powered by a battery, which had be able to deliver supply current for more than one year.
As data showed a rather low change rate, the following solution was found:
Microcontroller was all the time in power down mode. Only when data to be monitored left a certain allowed band, which was detected by an ultra low power analog circuitry, micro was awaked and stored according data.
Beside this, micro run with very low frequency.

Kai