# Q&A（FAQ）How to Calculate Electrolytic Capacitor Lifetime in case Ambient Temperature Changing?

## 1. Calculation in case that lifetime calculation conditions are changing

Supposing that using a power supply for [A] hours in condition [a], for [B] hours in condition [b], …… and for [X] hours in condition [x], and denoting the estimated lifetime in each condition by the symbols of La, Lb, ……Lx, the estimated lifetime [L] in the compound condition and the estimated lifetime in each condition is, ## 2. Example

Electrolytic capacitor Rated Temperature = 105℃ Basic Lifetime = 1,000H 45℃ (Estimated lifetime = 64,000H) / 8H 55℃ (Estimated lifetime = 32,000H) / 8H 65℃ (Estimated lifetime = 16,000H) / 8H

According to formula ①, The ambient temperature (Ta), applied to the above estimated lifetime [L], can be figured out by the following formula. As a result, Ta [57.2℃] is higher than average ambient temperature 55℃. It means that the actual operating condition would be severe than the condition operated at average ambient temperature continuously.

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