In recent years, the news of individual battery incidents
such as cell-phone and laptop fires has been eclipsed
by factory fires and large recalls of lithium-ion (Liion)
cells. Several large, well-known Li-ion cell suppliers
have been affected. The most notable event was the recall
of Sony batteries in 2005. Panasonic and, more recently, LG
Chemical have had fires affecting their Li-ion manufacturing
volume as well.
While these factors present challenges for the Li-ion supply
chain, the field failures of individual batteries result in the
potential for serious injuries, and the continuing growth of
handheld devices has spawned a healthy selection of aftermarket
battery pack suppliers. Counterfeit batteries have become
increasingly common and popular with consumers. Globally,
more than 5 million counterfeit cell-phone batteries have been
confiscated and destroyed by law enforcement officials.
IN THE NEWS
The unregulated supply represents a huge safety issue. In
November 2007, The Korean Times reported on the death of
an excavation worker. The cause of death was suspected to be a
cell-phone battery explosion. The cell phone was found in the
worker’s shirt pocket with the battery melted, and the worker’s
chest was burned.
This incident was remarkably similar to an event in China
reported by The Register in July 2007 where a welder died when
his ribs were broken after an apparent cell-phone explosion.
According to the article, “a Beijing spokesman for Motorola
said it was ‘highly unlikely’ that the company’s product was
to blame and ‘questioned whether the man was using a fake
Motorola cell phone or battery.’” Seemingly random battery
fires are often attributed to aftermarket or “fake” batteries.
Battery packs are no longer a simple configuration of cells.
They are carefully engineered products with many safety features.
The main components of a battery pack include the cells,
which are the primary energy source, the printed-circuit board,
which provides the intelligence of the system with features
such as the fuel gauge and protection circuitry, the plastic
enclosure, external contacts, and insulation.
Standards from several sources outline the safety features
that battery packs need in great detail. The most significant are
the IEEE 1625 and 1725 standards for laptop and cell-phone
batteries, respectively. Imitation battery packs often lack one or
more of these safety features. Typical violations include:
• The use of substandard or unqualified cells
• Mismatched components on circuit boards that may not provide
adequate performance
• Lack of a current/voltage or thermal protection circuit
• Lack of accommodation for normal cell swelling over time
• Nonexistent or obstructed gas vents
• Bad welds or solder joints
COMBATING COUNTERFEITERS
It is important to protect yourself as a consumer against the
dangers of knockoff battery packs. As an electronic design
engineer, it also is your responsibility to protect your company
from aftermarket packs. Fortunately, many options are available
to design-in protection against aftermarket batteries.
The most obvious is the form of the packaging and connectors,
but this approach can be circumvented by simple
measurements. And once a counterfeit or clone is available, the
original manufacturer would have to change the form factor,
which isn’t a trivial task.
Labeling such as stickers, certification markings, and holograms
are another possibility. Good, cheap scanners and color
copiers make these methods easy to reproduce, though. Webbased
registration is another idea, but it creates an inconvenience
for the user.
A challenge/response between the battery and the device
is a more secure approach. It requires a secret shared between
the host and the battery, random input, and an algorithm for
generating an output that is difficult to predict. Selection of the
correct authentication technique is about understanding the
tradeoffs to be made.
The design community must not neglect the danger of
counterfeit batteries. Imitation or aftermarket batteries have
resulted in public-relations issues for portable equipment
manufacturers because these counterfeits usually lack the quality
of the original battery. Single-cell lithium battery packs for
cell phones have received most of the media scrutiny.
However, multicell lithium packs are more complex and
have many more points of failure. Also, safety is more a concern
in industrial, military, and medical equipment when reliability
and safety intertwine.
The quantifiable impact of imitation battery packs on the
original equipment manufacturer includes increased safety
risks for customers, greater product returns due to non-performing
batteries, reduced customer satisfaction, and reduced
revenue for batteries supplied by the original manufacturer.
The intangible qualitative impact is the negative effect on the
device manufacturer’s brand-name equity.