Storage Performance
When an aluminum electrolytic capacitor is stored under
no load conditions for a long period of time, its leakage
current tends to increase slightly. This is due to a drop in
the withstand voltage of the dielectric caused by the
reaction of the anode oxide layer with the electrolyte.
When the voltage is applied to the capacitor, the leakage
current returns to its initial level because of the re-forming
action of the electrolyte (called voltage treatment). If the
storage temperature is high, the leakage current will
increase substantially. Therefore, it is desirable to store
capacitors at normal temperature level with no direct
sunlight. A voltage treatment is recommended when using
a capacitor stored for a long period of time. The treatment
for an individual capacitor is accomplished by charging
up to its rated voltage through a resistance of about 1 kΩ
and applying the voltage for approximately 30 minutes.
When a capacitor is already built into an appliance, the appliance must undergo aging. If the input voltage is
adjustable or the power supply that supplies power to a
module, first set the voltage to a low value (approximately
half the rated voltage) and let it run for about ten minutes.
Then, increase the voltage to the appropriate value little by
little while monitoring the working of a device.
If the voltage is not adjustable, turn on the switch and let it
run for about thirty minutes while confirming if the device
complies with the specifications. Then turn off the switch
before using the capacitor for practical applications.
Generally, if the capacitor has been stored within 2
years in the storage temperature range of 5~35o
C, the
capacitor can be used without voltage treatment.