DLR
Application Guidelines
1. Do not apply a reversed voltage.
Reverse polarity is not recommended. If a reversed
voltage is applied for a long time, the leakage current will
increase abruptly, which may cause a decrease in the
capacity, an increase in the internal resistance, and cause
electrolyte leakage or damage to the capacitor in some
cases.
2. Do not apply any voltage higher than the operating
maximum voltage.
Supercapacitors are rated with a nominal recommended
working or applied voltage. If an over voltage is applied to
the capacitor, the leakage current will increase abruptly
and the capacitor will become overheated, which may
cause a decrease in the capacity, an increase in the
internal resistance, and cause leakage or damage to the
capacitor in some cases. But, surge voltage can usually
be tolerated by the super capacitor.
3. Ripple Current
Supercapacitors have a higher internal resistance than
aluminum electrolytic capacitors and are more
susceptible to internal heat generation when exposed to
ripple current, this may cause a decrease in the capacity,
an increase in the internal resistance, and cause electrolyte
leakage or damage to the capacitor in some cases.
4. Charging and Discharging.
Supercapacitors can be charged using various methods,
including constant current, constant power, constant
voltage or by paralleling to an energy source, i.e. battery,
fuel cell, DC converter, etc. In general, characteristics of
constant current and constant resistance discharging are
respectively represented by the equation (1) and (2) below:
Discharging time (t) of constant current discharge
t = C x (Vo-V1) / l…..(1)
Discharging time (t) of constant resistance discharge
t = -CRIn(V1/Vo)…..(2)
t = discharging time(s)
vo = initial voltage (v)
v1 = terminal voltage (v)
l = current during back-up (A)
The maximum recommended charge current, I, for a super
capacitor is calculated as follows:
I = Vw / 5R
where Vw is the charge voltage and R is the super
capacitors DC ESR
Supercapacitor
5. Do not use in a circuit where quick charge and
discharge are repeated very often.
In a circuit where quick charge and discharge are
repeated very often, the capacitor will become
overheated, which may cause a decrease in the
capacitance, an increase in the internal resistance, and
cause electrolyte leakage or damage to the capacitor in
some cases. Reduce the charge and discharge currents
while selecting a capacitor with low internal resistance,
and make sure that the capacitor surface temperature
does not rise more than 10˚C.
6. Super capacitor life depends on the ambient
temperature.
The lifetime of super capacitor is seriously affected by
change in ambient temperature. If the temperature is
lowered by 10˚C, the lifetime will be approximately
doubled. As a result, it is recommended to use the super
capacitor at the lowest temperature possible to decrease
internal degradation and ESR increase. If the capacitor is
used at a temperature exceeding its maximum guaranteed
temperature, not only is its life shortened, but increased
vapor pressure of electrolyte or electrochemical reactions
may increase the internal pressure, and cause electrolyte
leakage or damage to the capacitor in some cases.
7. Voltage drop occurs during back-up operation.
In applications where the discharge current is large, or a
large current flows instantaneously, super capacitor may
not operate at the start of discharge because of the large
voltage drop (IR drop) caused by the capacitors internal
resistance (ESR). The formula for the voltage drop, Vdrop,
during a discharge at I current for t seconds is:
Vdrop = I(R + t/C)
8. Series Connecting of super capacitor.
A series connection can cause an imbalance in the
voltage across a super capacitor causing the capacitors
to have an over voltage which can cause electrolyte
degradation, excessive gas generation, increased ESR,
decrease in capacitance and reduced life. To prevent
voltage imbalance, passive or active voltage balancing is
recommended. Passive voltage balancing should be
performed using divider resistors placed in parallel with
the super capacitors. Using resistance values between100
Ω/F
to 470
Ω/F
are recommended.
®
3757 W. Touhy Ave., Lincolnwood, IL 60712 • (847) 675-1760 • Fax (847) 673-2850 • www.illcap.com
DLR
9. About vibration.
A terminal blank, a terminal bend, and a crease may occur
by adding too much vibration to a capacitor. When there
becomes too much vibration, please contact our company.
10. When used on a double sided printed circuit board,
do not design exposed circuit board traces under the
super capacitor.
An electrical short could occur if the super capacitor
electrolyte should leak onto the circuit board.
11. Do not store in high temperature and high humidity
conditions.
Avoid high temperature or high humidity or direct rays
when storing capacitors. Avoid direct contact with water,
salt water or oil, toxic gases, or dusty environment.
12. When soldering the super capacitor to the wiring
board, do not attach the body of the super capacitor to
the circuit boards.
If the body of the capacitor is attached directly to the
circuit board, the flux or solder can blow through the
mounting holes in the circuit board, possibly causing
internal damage to the super capacitor.
13. Do not overheat when soldered.
Excessive heat may cause deterioration of the electrical
characteristics of the aerogel super capacitor, electrolyte
leakage or an increase in internal pressure.
Supercapacitor
14. Circuit board cleaning after soldering.
Circuit boards can be immersed or ultrasonically cleaned
using suitable cleaning solvents for up to 5 minutes and
up to 60˚C maximum temperatures. The boards should be
thoroughly rinsed and dried.
Wave solder
Temperature
(°C)
220
240
250
260
Exposure time (seconds)
Recommended
exposure time
7
7
5
3
Maximum
exposure time
9
9
7
5
15. Be careful not to apply an excessive force to the
capacitor body, terminals or lead wires.
If the capacitor body is subjected to stress such as
grabbing, falling, bend, pushing or twisting after mounted,
its terminals may come off, leading to open, short or liquid
leakage.
16. Emergency procedures.
If a super capacitor is found to be overheating or starts to
smell, immediately switch off the unit’s main power or load
to stop operation. Do not expose your face and hands if
exposed to electrolyte. Wash exposed area thoroughly
with soap and water.
®
3757 W. Touhy Ave., Lincolnwood, IL 60712 • (847) 675-1760 • Fax (847) 673-2850 • www.illcap.com
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