Battery life calculation

The following is a battery life online calculator that calculates the actual working time of the battery based on battery capacity and load.

Battery working time calculator

Battery capacity  
mAh °C Operating temperature
+110°C Under,1% Time before failure (hours)  
IBAT (Max) IBAT (Typical)
nA nA


day day
year year
year(Consider self-discharge) year(Consider self-discharge)

Version 1.0.0

Model and capacity of common button lithium batteries
Model Capacity +110°C下的1% TTF
BR1632 120mAh 1900 hrs
CR1632 140mAh 1350 hrs
BR1225 48mAh 1900 hrs

The calculator calculates the battery's working time based on battery capacity and load. 
 among them:
 IBAT (Maximum) is the maximum battery current, which is given in the RTC data sheet. 
 IBAT (Typical) is a typical battery current defined at +25 ° C and nominal supply voltage, which is given in the RTC data sheet. 
 The operating time (days and years) of the backup battery is estimated using the formula Ah/A, where Ah is the battery capacity expressed in ampere-hours, and A is the load current expressed in amps.
 According to the Arrhenius model calculation, consider the backup battery working time under the condition of self-discharge of the battery:
 The life-acceleration test estimates the hours before the 1% failure (TTF) and the activation energy (EA). As the operating temperature increases, the self-discharge of the battery will significantly affect the overall operating life of the battery.
 In any case, assuming an activation energy of 1 eV, the TTF for several common batteries is given in the table below. In the calculation, the stress temperature (T2) is assumed to be +110 ° C (+383 ° K). Note that different manufacturers, different battery model serial numbers, may have different 1% TTFs, depending on manufacturing tolerances. Contact the battery manufacturer for reliability data of the actual model.