‘Revolutionising’
EV battery
management
TI unveils a EV battery management solution driving the move to more
reliable and efficient electric vehicles. By Neil Tyler
A s more vehicles become
electrified so there is a
need for improved levels of
functional safety that require much
higher levels of accurate battery
monitoring.
Tech companies are working hard
to improve battery-monitoring accuracy
in order to ensure that the vehicle’s
battery management system is able
to work more efficiently and is able to
monitor, in real time, the performance
of the individual battery cells.
It’s interesting that elegant
technology abounds in the latest EV
models but in the chassis underneath
there remains a complex mass of
components supporting its system of
batteries.
EVs are packed with battery
cells and, as such, currently require
extensive multi-cable solutions
to connect each cell to a battery
management system (BMS) that is
able to deliver the efficiency, longevity
and performance that’s required.
EV battery packs can stack up to
1000V and beyond to support the
demanding loads of the AC motor
and can comprise of hundreds of
cells stacked together in series.
Distributed battery pack systems are
able to support high-cell-count packs
by connecting multiple high-accuracy
battery monitors on separate printed
circuit boards called cell sensing
units.
However, operating a high voltage
battery pack in a vehicle imposes
tough conditions - wide operating
temperatures and vibration need
to be managed while the battery
management electronics are expected
to maximise operating range, lifetime,
safety and reliability.
Each cell, in such a system, is
connected via a complex network
of cables and wires to enable
performance monitoring and this has
raised issues around cost, size and
weight. As a result, there’s been a
growing realisation that these cables
and wires are proving a significant
drag on reliability, maintenance and
manufacturing costs.
Another issue arises in that to
accommodate the large quantity
of cells that are now required for
high powered automotive systems,
batteries are being distributed
throughout the available spaces in
the vehicle, which requires a sound
communication system.
To address these issues
companies are now developing
next generation BMS that operate
wirelessly, ending the need to use
the pounds of wiring found in current
solutions.
Wireless BMS
Texas Instruments has developed a
wireless BMS that not only removes
the need for bulky wired solutions,
but delivers improved EV reliability.
“EVs are packed with battery cells
and multi cabling, so in every EV the
BMS is an essential component. Each
battery cell has to be connected so
it can be monitored but, at present,
“Monitoring the
battery is critical
as is measuring
the voltage and
temperature
if you are to
guarantee that
the maximum
energy is being
extracted
between
charges.”
Ivo Marocco
that requires large
amounts of heavy duty
copper wiring to ensure
reliability. So our BMS is wireless,”
explains Karl-Heinz Steinmetz, TI’s
General Manager of Powertrain in
Automotive Systems.
In theory, removing these wires
and additional components will
reduce both weight and footprint and
improve the vehicle’s reliability.
“Battery management systems
are currently connected by wire using
a daisy-chain configuration - which is
widely perceived as safe. But while it
provides reliable communications it
is complex using a mass of cabling,
wires, connectors and isolation
components. The mechanical failure
of these components is a common
source of cable failures and can
prove costly to repair. Replacing
batteries is also proving to be ‘super’
expensive,” adds Steinmetz.
According to Steinmetz, the crucial
advantage of a wireless BMS is that
it significantly reduces the total cost
of ownership and eliminates the need
for maintenance-prone components.
“A wireless BMS reduces the
complexity of the design removing
connectors and other components. In
a wireless scenario there is a direct
link from the BMU to each wireless
node that improves the reliability of
the complete system.”
TI’s solution is intended to
empower automakers helping them
to reduce the complexity of their
designs, improve reliability and
reduce vehicle weight to extend
driving range.
But not only that, it also helps to
reduce assembly costs too.
20 9 February 2021 www.newelectronics.co.uk
/www.newelectronics.co.uk