Text preview for : HP AN 372-2 Application Note.pdf part of Agilent HP AN 372-2 Application Note Agilent HP AN 372-2 Application Note.pdf



Back to : HP AN 372-2 Application N | Home

Agilent AN 372-2
Battery Testing
Application Note




An electronic load can be used to discharge batteries of various
chemistries to determine actual capacity, capacity retention,
and internal impedance.
Introduction




Increasing demand for portable DC Whether testing batteries in R&D or
power has risen from improvements production environments, the test
in battery and motor design technol- requirements for each of the different
ogy. More than ever before, portable battery types are basically the same.
DC powered products have become Figure 1 shows a common test config-
available in many diverse applications. uration. In general, the testing of a
Rechargeable batteries appear in all battery involves discharging it over
types of products from analytical a period of time to determine several
electronic equipment to power tools specifications. This application note
and toys. In some instances, these will concentrate on the test of second-
diverse applications pose different ary batteries because they require Figure 1. Common Test Configuration
requirements on the source of DC additional tests involving recharging.
Power. Fortunately, availability of Nickel-cadmium batteries, in partic-
many types of battery chemistries ular, are discussed because they are
yield unique characteristics. Table 1 the most universally used type of
contains just some of the different secondary battery in today's demand-
battery types and their advantages. ing applications.




Table 1. Characteristics and Applications of Different Battery Types

Nickel- Gelled Lead Lithium Carbon Alkaline Silver Mercuric
Cadmium Acid Zinc Oxide Oxide

Volts/Cell 1.2 2.0 1.5 to 1 1.5 1.5 1.5 1.4

Applications portable standby service, memory backup, average use good general button-sized button-sized cells
equipment, rechargeable pacemakers, purpose battery cells for watches for watches and
rechargeable electronic and hearing aids hearing aids
door locks,
emergency
locator
transmitters

Charge CC CV, float charge N/A N/A N/A N/A N/A
Method

Cycle Life 500+ cycles 200 cycles N/A N/A N/A N/A N/A

Life 3 mos. 1 year 5 to 10+ years 1 to 5 years 5% loss/yr. 6% loss/yr. 4% loss/yr.
(Charged) (