SOC defines the remaining energy
capacity available in the battery. SOH
looks at the degradation level of a
battery's ability to store energy. Both
parameters are direct indicators of the
end system's performance and available
runtime."
Jackie Hui
Principal System Engineer, Automotive wBMS Solution, Analog Devices
measurement is inaccurate, then the vehicle could
run out of charge unexpectedly, and the user could
end up stranded on the side of the road.
Accompanying SOC as another important battery
metric is SOH.
SOH is a metric that describes the current maximum
capacity of a battery relative to its maximum
capacity as provided by the battery manufacturer.
Effectively, SOH is a measure of the overall health of
a battery as compared to a fresh battery, factoring
in conditions such as cell aging, cycling, and
temperature.
This metric is important because a battery's
degradation level changes the way it operates;
hence, the BMS must be able to optimize functions
accordingly. For example, a cell's charge and
discharge time will become faster with aging. Hence,
a proper understanding of SOH can enable battery
lifespan optimization, safety management, and
performance assurance.
C h a p t e r 1 | S t a t e O f C h a r g e ( S O C ) a n d S t a t e o f H e a l t h ( S O H )
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8 Industry Experts Discuss Battery Management Solutions
