Canique Climat - Battery Life
How do we calculate battery life?
We calculate battery life in 2 different ways.One way is a real-life measurement of the sleep current and the wake-state current of Canique Climat using a laboratory power supply. Using this measurement and knowing the energy stored in a battery and its self-discharge rate, we can forecast how long the battery is going to last.
The second way is a cross-check if our measured figures make sense. We calculate the current that should be consumed in sleep and wake-state, solely based on figures stated in technical documents of the components that we use. Summing up these currents should be equal to what we have measured.
At last we verify our estimation for plausibility in a long-term real-life experiment. This involves setting up a Canique sensor and having it run for more than 1 year. From the voltage drop in the battery we can estimate whether our expected figures can be achieved.
To sum it up, the high battery expectancy stated here, is by no means marketing speech.
10 years battery life with a 2500 mAh AA Alkaline battery
The following table shows Canique Climat's calculated battery lifetime with a 2500mAh Alkaline battery at room temperature. The estimated battery self discharge rate is 15-20%. The transmission (TX) Power is set automatically depending on the distance between sensor and base station and depending on obstacles.
Transmission interval
Battery Life @ Min TX Power
Battery Life @ Max TX Power
30s
10 years / 16* years
10 years / 11* years
60s
10 years / 27* years
10 years / 20* years
*) The values with an asterisk are those that we calculated. But we cap them to 10 years since a typical alkaline battery itself has a shelf life of 10 years. Hence the real/practical estimated battery life time is about 10 years.
14-20 years battery life with an Energizer Lithium 3000mAh battery
The next table shows Canique Climat's calculated battery lifetime with an Energizer Lithium 3000mAh battery. Note that this battery won't degrade in performance at very low temperatures. The estimated battery self discharge rate is 15%.
Transmission interval
Battery Life @ Min TX Power
Battery Life @ Max TX Power
30s
20 years
14 years
60s
20 years / 35** years
20 years / 25** years
**) The values beyond 20 years are theoretical values since the Energizer Lithium battery has a shelf life of 20 years.