The Important Information/Disclaimer is incorporated in the catalog where these specifications came from or

available online at www.avx.com/disclaimer/ by reference and should be reviewed in full before placing any order.

24

4.3 ENHANCING THE POWER CAPABILITY OF

PRIMARY BATTERIES

When electronic equipment is powered by a primary (non rechargeable)

battery, one of the limitations is the power capability of the battery.

In order to increase the available current from the battery while maintaining

a constant voltage drop across the battery terminals, the designer must

connect additional cells in parallel, leading to increased size and cost of

both the battery and the finished product.

When high power is only required for short periods, more sophisticated

approaches can be considered. The traditional approach involves using a

high power rechargeable battery, charged by a low power primary cell.

A far superior solution, however, is the use of a BestCap® Supercapacitor,

which is a device specifically designed to deliver high power.

Traditional design:

Design using BestCap®:

Primary

Battery

Rechargeable

Battery

Battery Powered

Equipment Requiring

High Current Pulses

Primary

Battery

BestCap

Battery Powered

Equipment Requiring

High Current Pulses

®

BestCap® Supercapacitor benefits to the designer are:

• Substantially lower voltage drop for pulse durations of up to 100msec.

• Substantially lower voltage drop at cold temperatures (–20°C).

• Discharge current limited only by the ESR of the capacitor

The following analysis compares a primary battery connected in parallel

to a Lithium Tionil Chloride, to the same primary battery connected to a

BestCap® Supercapacitor. Various current pulses (amplitude and duration)

are applied in each case.

BestCap® 5.5V 100mF

BestCap® 3.5V 560mF

Pulse

Voltage

Drop (mV)

BestCap® Supercapacitors

Voltage

Drop (mV)

rechargeable battery

250mA / 1msec

25

150

500mA / 1msec

50

220

750mA / 1msec

75

150

200mA / 100msec at -20°C

232

470

Pulse

Voltage

Drop (mV)

BestCap® Supercapacitors

Voltage

Drop (mV)

rechargeable battery

250mA / 100msec

50

190

500mA / 100msec

100

350

750mA / 100msec

152

190

1500mA / 1msec

43

220

1500mA / 100msec

305

350

750mA / 100msec at –20°C

172

470

Additional

Characteristics

BestCap®

Rechargeable Battery

Maximum discharge

current (single pulse)

Not limited

5A Maximum

Number of Cycles

Not limited

40K to 400K

(to retain 80% capacity)

BestCap® Ultra-low ESR

High Power Pulse Supercapacitors

Enhancing the Power Capability of Primary Batteries

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