C h a p t e r 1
One of the key battery performance
indicators used in any BMS is SOC.
SOC is a metric that describes the
quantity of charge remaining in a battery
relative to its maximum capacity. This
metric is important because it helps
a BMS dynamically optimize battery
performance to ensure optimal battery
usage, safety, and health. For example,
parameters like charging and discharging
profiles will be used by the battery's SOC;
hence, a good understanding of SOC can
largely influence system operation.
In general, SOC can be calculated in
many different ways, ranging from
simple voltage-based measurements to
complex algorithms involving intensive
computation. In either case, the accuracy
of SOC measurements ultimately boils
down to the accuracy of the supporting
components and circuitry for taking the
necessary measurements. For this reason,
passives, like resistors and capacitors,
need to offer extremely tight tolerances
that don't deviate across temperature or
age.
Consider the example of an EV. The SOC
measurement for an EV will indicate to
the user how much range they have left
before the car shuts down. If the SOC
STATE OF CHARGE (SOC) AND
STATE OF HEALTH (SOH)
Scott Blackburn
Director of Automotive, Business Development, Vishay
To accurately estimate the lifetime
of your battery and when you need
to change it, you need to have
accurate measurements over time
and temperature. Then you need a
realistic algorithm that makes the
calculation taking into account all
of this information for every cell."
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8 Industry Experts Discuss Battery Management Solutions
