The Garage 361

EV
12-volt batteries, the
EV battery of choice!
Following its recent findings concerning the ongoing demand for 12-volt batteries, Ecobat
Battery can now release further evidence for this long term aftermarket requirement,
following research into electric vehicle (EV) breakdown statistics.
As it previously made clear, whether an EV incorporates an
internal combustion engine (ICE) with a 48-volt or 350-volt
battery in hybrid form, or uses a 400-volt plus battery as a
fully battery powered variant, a ‘traditional’ 12-volt battery is also
fitted. The revelation comes however, in the fact that in common
with their ICE powered counterparts, the number one cause of EV
breakdown also turns out to be failure of this battery! But why?
Since the UK launch of the Tesla a decade ago, and following
changes in government legislation, many other vehicle
manufacturers (VM) have added full EVs to their product ranges. As
a result, they and their partners have invested hundreds of millions
of pounds to develop the electric motors, control systems and high
voltage (HV) battery packs to make the move from relying on an ICE,
to using fully electric propulsion achievable.
However, as stated earlier, in the quest to develop these new
technology vehicles, not everything is new, as 12-volt systems remain
integral to EVs to enable them to perform vital functions. These
include not only powering the lighting system, both internal and
external, but the central locking, alarm, and other security features.
It also powers the vehicles onboard computer and diagnostic
systems and plays a role in starting the main HV battery pack.
These systems put significant load on the 12-volt battery and
whereas in vehicles incorporating an ICE after providing a big burst
of electrical energy to power the starter motor, it is recharged by
an alternator and managed by the vehicle’s electronic control units
(ECU), a process that has been refined over many years, in an EV,
the 12-volt battery is performing a much more cyclic function, being
charged by the high voltage battery and discharged by the 12-volt
systems that rely on it.
Irrespective of whether the vehicle is an EV or incorporates
an ICE, the maintenance of its 12-volt battery is down to the
parameters set in the ECU’s battery management system, and this is
where there is a potential conflict of interest.
It’s well known that discharging a standard 12-volt SLI (starter,
ignition & lighting) battery beyond 50% will reduce its life
expectancy. However, largely due to the fact that range anxiety
is one of the key barriers to EV uptake, VMs want to maximise the
range capability that they can offer drivers. To do this the battery
management system has to make a compromise between charging
the 12-volt battery to keep it in top condition, or providing for the
vehicle’s optimum range, which can result in an undercharged 12-
volt battery, affecting its useable life.
A further impact on the life of the 12-volt battery comes with the
advanced technology inbuilt into an EV. Its inherent connectivity
and the plethora of apps it can run, such as to remotely ’wake it
up’ and activate the 12-volt system, for example, can require 5,000
activations per day, which can seriously discharge the 12-volt
battery and leave the driver with a lifeless car.
Although the VMs work hard to update their systems when
they find these issues, in the meantime they provide a welcome
opportunity for the aftermarket because, despite many workshops
being wary of working on EVs, it should be encouraging for them to
know that the most likely cause of a breakdown, is due to one of the
components that they are most familiar with.
Therefore, before surrendering an EV to the franchised dealer
network, workshops should first assess the condition of the 12-
volt battery and if that’s the issue, providing they use the correct
protocols for working on a HV vehicle, installing a replacement not
only solves a problem for the owner, but it also makes a profitable
job for the business.
As a result of its findings and to further assist the independent
service and repair sector, Ecobat Battery has proactively updated its
application data on its online Battery Finder, as well as its Numax and
Lucas data on MAM Autocat, to provide all the necessary application
links to these vehicles.
For further details, please visit Ecobat Battery at: www.
ecobatbattery.com
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26 THE GARAGE
21 Feature EV.indd 6 27/03/2024 13:52