Progress Solar/Wind SLT 700 Series Operator's Manual page 83

Calculation example using the 5h and the 20h rating
The C5 rating is 75Ah. The t1 rating is 5h and I1 is calculated:
The C20 rating is 100Ah. The t2 rating is 20h and I2 is calculated:
The Peukert exponent is:
A Peukert calculator is available at
support-and-downloads/software#peukert-calculator.
Please note that the Peukert exponent is no more than a rough approximation of reality. In case of very high currents, the battery
will give even less capacity than predicted by a fixed exponent. We do not recommend changing the default value in the battery
monitor, except in the case of lithium batteries.
Page 45
Manual - BMV-712 Smart
http://www.victronenergy.com/
Battery capacity and Peukert exponent