mkove electronics

Peukerts Law


Peukert's Law is an old law which accurately predicts the available capacity of a battery under a constant load.[1]


It is useful if a fixed load is attached to a battery to predict the time until the battery will become flat. However with a varying load it will not reflect the total available capacity of the battery and internal resistance is a more relevant factor to state of charge.


For example if a large load is applied to a battery and Peukert's Law predicts a significant reduction in capacity, the large load can be removed, a small load applied and almost all of the original capacity of the battery will still be available. What has been lost has been lost to internal resistance, not to Peukerts Law.


Peukert's Law has an immediate affect. Internal resistance however has a continual affect on the state of charge of the battery and is calculated at all times during charging and discharging.




[1] Peukerts. Wikipedia Peukerts Law.