Peukert’s law

The relationship between cmrent, discharge time, and capacity for a lead acid battery is approximated (over a certain range of current values) by Peukert s law ... 

W. Dependency of the capacity on the discharge current and the temperature. Peukert s law... 

So long as the discharge currents remain reasonable (around 1 C), the capacity depends only very little, if at all, on the regime of discharge, but appears to be more sensitive to temperature than is the case for a lead-acid battery. Peukert s law, introduced for lead-acid batteries, describes the dependency of the capacity on the discharge current. It is expressed thus ... 

Although it is called a law, Peukert s law is in fact an empiricaUy-detemiined expression and does not have the nature of a fundamental law. 

The efficiency factor of a discharging battery is expressed by the Peukert s law. W. Peukert, a German scientist (1897), devised a formula expressing loss at a given discharge rate in Peukert numbers. Because of the sluggish behavior of lead acid, Peukert numbers apply mostly to this chemistry. They help to calculate the capacity under various load conditions. 

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