megatrends

Megatrends
What can be done to ensure the safety
of EVs not only in crash situations, but
also post-crash, where often small
garages and warehousing may be
involved in the storage or repair of the
vehicle?
The solution is greater dissemination of EV
knowledge through accurate specific data and
training. The media has commented on the
slow take up of EVs, yet in the UK alone there
are 50,000 Honda and Toyota HEVs already on
the road in addition to battery EVs. At
Thatcham we’re proud to have been central to
this up-skilling, as being non franchise-specific
we’ve been able to provide knowledge and
training across the industry to many sectors
and are continuing to do so. Vehicle recovery
specialists, emergency services, and even HM
Customs and Excise have received training
and equipped themselves with the tools and
necessary PPE [personal protective
equipment].
Incidents involving laptop batteries or
the NHTSA incident we referred to
have led to questions about the safety of
lithium-ion (Li-ion) batteries, yet they
remain the battery of choice for the
majority of EVs. What is the view among
safety experts of the Li-ion battery
versus other energy storage solutions?
Li-ion battery technology is the choice for the
majority of EVs because of its energy density.
That is only logical as the manufacturers need
range performance to make EVs a practical
alternative to ICEs. Yes, there have been
incidents with Li-ion batteries, but put this
into perspective with volume: according to
Cisco Systems, by the end of 2013 there will
be more smartphones than people on earth.
That’s a lot of Li-ion batteries, and
comparatively few incidents. Vehicle engineers
have learned how to safely package fuel tanks,
SRS airbags and LPG, and we are already
seeing developments in battery handling.
What is the procedure for post-crash
EV batteries?
There is no set procedure for batteries postcrash.
Actions depend on the incident. If the
vehicle is flood damaged or otherwise badly
damaged enough to be deemed a total loss, it
will probably go to a salvage specialist intact.
The better salvage companies have handling
procedures.
The exception really is Renault, with its
battery lease scheme, where most aspects are
covered by Renault, including battery shipment
costs to France.
If the battery is removed post-crash, for
vehicle repair, it should be clearly labelled and
identified, and stored somewhere dry at a
suitable temperature. It should be
remembered that although the battery lockout
or cut-off will have been performed, the
battery will still be in whatever charged state
it was in prior to this.
PSA and Bosch are jointly developing
Hybrid Air, a hybrid solution which will
enable the production of battery-free
hybrid cars. Apart from the efficiency,
cost and energy storage advantages that
PSA has mentioned, could there be any
safety advantages in removing entirely a
Li-ion battery from a vehicle?
At Thatcham we are of course aware of
Hybrid Air, but we’ll let PSA and Bosch, and
others, mature the technology before we
comment on this specifically. There are
efficiency and energy storage issues to
overcome too, not least of which will be the
temperature changes induced by changes in air
density. This will be an issue for the storage
tank, and the mechanical pump and motor. And
although very rare, a storage system is
susceptible to failure too. Yes, we’d always
advocate removal of any potentially harmful
component from a vehicle, such as a Li-ion
battery, but so far we have seen little evidence
of unacceptable safety risk.
What is the best way to cool batteries -
coolant or air?
There are advantages and disadvantages to
both methods. Water cooling works well, but
one notable incident in an American safety test
was as a result of battery shorting in
conjunction with a coolant leak. Air cooling is
simpler, and more energy efficient. The
proposed lithium-air batteries, as the name
implies, are open to air so self-cool to a degree.
But moisture content in the atmosphere is an
issue that manufacturers have to overcome.
Hybrid powertrains add considerable
weight to a vehicle, especially one which
is also available with an ICE. What
impact does this additional weight have
on developing safety technology and
safety testing for a vehicle?
There has been some, as yet unconfirmed, data
from the US that the additional mass is
resulting in a reduction in occupant injuries in
HEVs and PHEVs, but the weight is not an issue
35 Automotive World Megatrends magazine | www.automotiveworld.com Q1 2013