Bonsoir, ESR causes power dissipation, I ripple RMS exp 2 * ESR.
The internal electrolyte hot spot temperature is raised by the dissipated power, so life is shortened and thermal runaway is possible.
Thus the ESR measurement is normal at two ripple frequencies
2X mains for FW rectifiers, 100 or 120 Hz
SMPS switch frequency, usually between 20....200 kHz
The rated temperatures ( 85, 105, 135 degrees C) of lytic is for a 2000 hrs service at rated ripple currents and ambient surface temperatures.
After 2000 hrs th¨¦ ESR Can increase and capacity decrease by 20-50%.
Hope that this is of interest
Enjoy,
Jon
Jean-Paul