Abstract: A simulator, in particular for simulating thermal batteries, the simulator delivering an output voltage U.sub.bat across output terminals thereof, said output voltage being a function of a current I.sub.out delivered, into a load connected to said terminals, and of an e.m.f. parameter. E.sub.g and of an internal resistance parameter R.sub.g that are determined from simulation profiles that give successive values taken by said parameters under real battery operating conditions during an active life cycle of a given battery. The simulator includes computer equipment delivering the simulation profiles in the form of e.m.f. references C.sub.Eg and internal resistance references C.sub.Rg to a battery simulation card which, in order to generate the output voltage U.sub.bat of the simulator at the output of said voltage programmable power supply feeds said power supply with a battery voltage reference C.sub.