Peukert coefficient

This Peukert coefficient, close to 1, giving a capacity independent of the duration of discharge, may lead us to choose a linear model of the dependency of the capacity on the discharge current. For instance, for an NCA element with poor capacity, we find the following values at 25°C C= 10.5 (Ah)-0.276.1 (A). 

Figure 5.4. Discharge time as a function of the current for different Peukert coefficients...

This energy is measured not only in Joules (1 J = 1 W s) but also in watt-hours (1 Wh = 3600 J.). Both the maximum ampere-hour capacity and the watt-hour energy depend on the amount of reactants in a battery at the start of discharge. As the discharge current increases, both the discharge voltage and the reactant utilization coefficient diminish. A number of attempts to find a relationship between the actual battery capacity and the discharge current were reported. An approximation found in 1897 by Peukert for lead acid batteries is sometimes used ... 

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