VOLTAGE MEASUREMENT
ACCURATE AND FLEXIBLE
BATTERY TESTING
How to perform battery testing effectively using the EX1401
isolated thermocouple and voltage measurement instrument
// CHRIS GIBSON
Today, advanced batteries are widely
used in transportation, commercial
industries, aerospace and defense
industries, as well as in portable electronic
devices. Battery manufacturing companies
put a lot of effort into maximizing
the batteries’ life and performance so
that electronic devices keep operating as
long as possible before running out of
battery power.
Batteries can be dangerous because they
can store high amounts of energy and can
explode, potentially causing serious
accidents or injuries. However, we all use
them every day. For example, lithium-ion
batteries are used in clean-air and energy
storage applications such as portable
chargers. Nickel-based batteries are used in
air and rail transportation, standby power
applications and emergency lighting.
Batteries need to be robust, reliable
and capable of being used in extreme
conditions to ensure that they cause
no harm to humans under any
circumstances. Therefore, batteries must
be tested with high accuracy to ensure
their proper operation.
COMMON MODE NOISE
In battery life cycle testing, multiple cells
are linked and tested at once to increase
the test throughput. Initially, the voltage of
each individual cell can be as low as a few
volts. However, after stringing together
cells in series, the total voltage becomes
much higher. During the test, a voltage
DAQ instrument is used to take a voltage
measurement from each battery. However,
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a high common mode voltage is generated,
along with so-called common mode noise,
causing the acquired data to become very
unreliable. Because the common mode
voltage is high relative to the actual voltage
of the batteries, it is difficult to distinguish
between the noise and the actual signal in
the acquired data. As a result, data analysis
becomes nearly impossible or the test
results become very inaccurate.
The EX1401 Isolated Thermocouple and
Voltage Measurement Instrument provides
up to 500V of channel-to-ground isolation
to safeguard against high common mode
noise. Each individual channel of the
EX1401 is isolated and has exceptional
input protection across a wide range of
operating conditions. Not only can it
ensure measurement integrity, but it
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