Introduction of Battery Testing
A
very important term to know when talking about mobile device batteries is the
“charging” or “discharge” test. These are typically done by having you use your
phone for an amount of time (usually called a usage period) and then comparing
how much power it has left to see if it can be recharged.
This
is different from a true “capacity” test, which looks at how many times a cell
can be charged and still retain its charge. True capacity tests usually require
expensive equipment that only a few companies have.
Voltage tests
A
very important test for any new battery is to determine its voltage limit. This
is done by testing the battery at one-half of its capacity and then seeing how
long you can use it before it stops holding a charge.
The
longer you can use the battery, the higher its voltage limit will be! It is
prudent to do this test initially as batteries lose their hold over time due to
usage.
Current tests
Many
companies have their own set of standards for how they test new cell phone
batteries. Some use statistical methods to determine if there is a difference
in battery testing performance between the two products. Others compare the overall
capacity of a battery over time or measure voltage levels at different points
during discharge to get an average value.
Some
even put the product into a charger and watch it charge! This is called
“charge-rate testing” because it determines how fast a battery can re-juice
after being drained.
All
of these strategies are used to assess whether one brand’s cells are more
effective than another’s at maintaining power, but none take into account
potential differences in safety. That could be due to improper balancing,
something that some manufacturers do not check before shipping,
or potentially harmful additives like cobalt, lithium, or manganese that
differ among brands.
Temperature tests
The
next test we will do is to determine how well your battery performs at its
highest temperature. This can be done by doing an extremely high heat discharge
or using the battery, or both!
To
perform this test, you need to fully understand what kind of cell chemistry
your battery has. Different chemistries require different-sized thermal
protection layers to work properly.
Never
leave your device unattended during these tests as possible burning and
explosions are very real possibilities!
Capacity tests
The
most common way to test battery capacity is by doing what they call charge-discharge
cycles. For this test, you need a source of power for the discharge (take away)
cycle and a time marker when the battery is fully charged.
There
are two main reasons to determine a battery’s capacity. First, we
want to know how much energy it can hold so that we can predict how long it
will last. Second, because some batteries lose their strength over time, we
want to make sure our current pack of batteries will still work
properly with your device.
Electrolyte tests
An
important part of any new battery’s life is how it de-gels or loses its charge
over time. Batteries will lose some of their capacity to hold a charge as they
use up chemical components, and these chemicals weaken and eventually disappear
(leak out) from the cell.
This
is called electrolysis and happens when current flows through the battery,
causing oxidation and reduction reactions that produce gas and water,
respectively. The gases are what cause problems in some cells – if too much
builds up, the pressure can lead to the battery to explode or rupture.
If
you look at almost any smartphone today, you will find that most batteries have
an insertion tool that users insert into the device. This is to test
the quality of the battery. These tools usually consist of very fine
needles that pierce the protective layer coating the positive
electrode, creating a small hole.
If
there is no resistance to the needle going in, then the material is not
sufficiently thick and strong to prevent electrons from flowing easily between
the liquid inside the cell and the surface of the negative electrode.
Comments
Post a Comment