Ordered and/or tested the FR and FS and both were better( as expected) than the FC. Settled (for now) on the FM. For the values I was using, it had a somewhat lower ESR. I may also try the 1000@35 FS. Thanks for the reply.

There have been suggestions for derating polymer electrolytics to below the rated values. I've seen documents that recommended this and some that indicate that derating isn't required. The documents recommending derating are often old or refer to old documents. Do polymer caps of this type still require derating for reliability?

If they require derating, why would the manufacturer give them their rated voltage?

This is the basic type of capacitor I'm referring to and included simply to eliminate other caps that use similar names.
https://www.mouser.com/datashe...

From what I've found, the endurance of a liquid electrolytic cap is determined by the loss of electrolyte. If a cap is rated for 1000 hours. That's typically for a straight run test. How would the life vary if the cap is intermittently heated to its rated temperature (105C). Maybe for an hour at a time then cooled back to 30-40C (just a random number). Would the life still be 1000 hours?

Does it make a difference in the life expectancy if the cap is heating from ripple current (internal heating) instead of from the external ambient temperature?

Why do polymer capacitors...

Plague caps?

I'm looking for suggestions for electrolytics that are 10mm diameter and up to 25mm tall, through-hole radial capacitors with 5mm lead spacing. The value needs to be in the range of 330uF to 470uF. I typically use 35v caps due to their lower ESR vs 16v caps. Currently, the Panasonic FC is being used but the FM series is under consideration.

This is for the primary side of a switching power supply in a car audio amplifier.

Is there a way to calculate power dissipation in a capacitor to predict which will operate at a lower temperature? For example, a 470uF may have a...