6
one or more days of data will be acquired from the instru-
mented MUVs/RTMs under normal operating conditions.
The measured data will be used for developing a robust
laboratory test standard for MUV/RTM LIBs and to
develop a “torture track” within the NIOSH Experimental
Mine. The measured mechanical shock and vibration data
will be used to develop an accelerated life test so that mul-
tiple years of LIB use can be represented in a few months
of time using laboratory vibration testing on an electrome-
chanical shaker. The temperature and relative humidity will
be used as thermal conditions for the laboratory testing.
Identify Existing Environmental Standards/Regulations
and Develop a Comprehensive Environmental Test
Procedure
As discussed in the literature review above, numerous test
standards for LIBs already exist. However, these are not
necessarily based on real-world operating conditions, espe-
cially the conditions encountered in mining. We plan to
thoroughly review existing LIB standards/regulations to
ensure all potential environmental concerns are addressed
in our test procedure. The anticipated components of the
test include the following:
1. A drop test to account for unintentional mishan-
dling of an LIB prior to installation
2. Shock and vibration applied to LIBs at ranges of
temperature and SOC
3. Immersion of the LIB in electrically conductive
“mine water.”
The drop test will specify the drop height, orienta-
tion, and surface. The drop height will likely be roughly
1 m, as this is reasonably representative of the height at
which a person would carry an object. The battery could be
dropped so that it lands on a corner, or it could be dropped
to land flat on its bottom surface. The surface could range
from pea-sized gravel to concrete. The drop test is impor-
tant because it could cause cracks in the case that would
subsequently allow moisture to enter.
The mechanical shock and vibration tests will be con-
ducted across a range of temperatures that encompasses the
minimum and maximum temperatures observed in field
conditions at regularly spaced intervals, for example every
10°C. The relative humidity for these tests will also be based
on field measurements. Because LIB vibration response
depends on SOC, the SOC will be varied from 20% to
100%, for example. At each combination of conditions, the
device under test will be tested for a set number of hours
before moving on to the next combination of conditions.
Once a complete “cycle” of shock and vibration tests is
complete for all combinations of temperature, relative
humidity, and SOC, an immersion test will be conducted.
The immersion test will be conducted by placing the
LIB into a tank of “mine water” which will contain con-
taminants that are representative of mining. The purpose
of this is to ensure that the liquid is electrically conduc-
tive. Once the LIB is lowered into the liquid, the LIB will
be kept in the liquid until air bubbles are not observed.
After the battery is lifted out of the tank, it will be observed
for enough time to ensure no adverse events will occur, 24
hours for example.
The details of each of the aforementioned tests will be
determined after completing our review of applicable stan-
dards/regulations. The individual tests will follow the stan-
dards when they are appropriate for the mining application.
However, modifications will be made to the procedures to
improve the tests’ representations of mining conditions.
Determine the Environmental Susceptibility of Mine
Utility Vehicle and Rubber-tired Mantrip Lithium-ion
Batteries
In order to determine MUV/RTM LIB environmental
susceptibility, the test procedure described above will be
applied in a laboratory setting. These tests may be con-
ducted internally at NIOSH or at an outside laboratory.
However, because it is expected that the cost associated
with conducting the above tests at an outside laboratory
will be cost prohibitive, we expect to conduct these tests at
NIOSH Pittsburgh Mining Research Division. Tests will
first be conducted at mechanical shock and vibration levels
that represent field conditions. If these tests do not result in
adverse LIB events, such as a voltage drop, visible damage,
or indication of thermal runaway, the mechanical shock
and vibration levels will be increased incrementally in an
attempt to establish the levels that would cause adverse
events.
To conduct these tests internally, specialized test facili-
ties and apparatuses will be developed within the NIOSH
Experimental Mine which has controllable fresh air flow
and multiple boreholes to the surface. In addition, the
Experimental Mine stays at a consistent temperature of
roughly 13°C to 16°C (55°F to 60°F) year-round. This is
expected to be roughly halfway between the minimum and
maximum temperatures at which the LIBs will be tested.
The primary apparatuses that would be developed or
purchased include a drop test machine, a temperature/rela-
tive humidity chamber, and an immersion test apparatus.
The drop test machine will lift the tested battery to the
one or more days of data will be acquired from the instru-
mented MUVs/RTMs under normal operating conditions.
The measured data will be used for developing a robust
laboratory test standard for MUV/RTM LIBs and to
develop a “torture track” within the NIOSH Experimental
Mine. The measured mechanical shock and vibration data
will be used to develop an accelerated life test so that mul-
tiple years of LIB use can be represented in a few months
of time using laboratory vibration testing on an electrome-
chanical shaker. The temperature and relative humidity will
be used as thermal conditions for the laboratory testing.
Identify Existing Environmental Standards/Regulations
and Develop a Comprehensive Environmental Test
Procedure
As discussed in the literature review above, numerous test
standards for LIBs already exist. However, these are not
necessarily based on real-world operating conditions, espe-
cially the conditions encountered in mining. We plan to
thoroughly review existing LIB standards/regulations to
ensure all potential environmental concerns are addressed
in our test procedure. The anticipated components of the
test include the following:
1. A drop test to account for unintentional mishan-
dling of an LIB prior to installation
2. Shock and vibration applied to LIBs at ranges of
temperature and SOC
3. Immersion of the LIB in electrically conductive
“mine water.”
The drop test will specify the drop height, orienta-
tion, and surface. The drop height will likely be roughly
1 m, as this is reasonably representative of the height at
which a person would carry an object. The battery could be
dropped so that it lands on a corner, or it could be dropped
to land flat on its bottom surface. The surface could range
from pea-sized gravel to concrete. The drop test is impor-
tant because it could cause cracks in the case that would
subsequently allow moisture to enter.
The mechanical shock and vibration tests will be con-
ducted across a range of temperatures that encompasses the
minimum and maximum temperatures observed in field
conditions at regularly spaced intervals, for example every
10°C. The relative humidity for these tests will also be based
on field measurements. Because LIB vibration response
depends on SOC, the SOC will be varied from 20% to
100%, for example. At each combination of conditions, the
device under test will be tested for a set number of hours
before moving on to the next combination of conditions.
Once a complete “cycle” of shock and vibration tests is
complete for all combinations of temperature, relative
humidity, and SOC, an immersion test will be conducted.
The immersion test will be conducted by placing the
LIB into a tank of “mine water” which will contain con-
taminants that are representative of mining. The purpose
of this is to ensure that the liquid is electrically conduc-
tive. Once the LIB is lowered into the liquid, the LIB will
be kept in the liquid until air bubbles are not observed.
After the battery is lifted out of the tank, it will be observed
for enough time to ensure no adverse events will occur, 24
hours for example.
The details of each of the aforementioned tests will be
determined after completing our review of applicable stan-
dards/regulations. The individual tests will follow the stan-
dards when they are appropriate for the mining application.
However, modifications will be made to the procedures to
improve the tests’ representations of mining conditions.
Determine the Environmental Susceptibility of Mine
Utility Vehicle and Rubber-tired Mantrip Lithium-ion
Batteries
In order to determine MUV/RTM LIB environmental
susceptibility, the test procedure described above will be
applied in a laboratory setting. These tests may be con-
ducted internally at NIOSH or at an outside laboratory.
However, because it is expected that the cost associated
with conducting the above tests at an outside laboratory
will be cost prohibitive, we expect to conduct these tests at
NIOSH Pittsburgh Mining Research Division. Tests will
first be conducted at mechanical shock and vibration levels
that represent field conditions. If these tests do not result in
adverse LIB events, such as a voltage drop, visible damage,
or indication of thermal runaway, the mechanical shock
and vibration levels will be increased incrementally in an
attempt to establish the levels that would cause adverse
events.
To conduct these tests internally, specialized test facili-
ties and apparatuses will be developed within the NIOSH
Experimental Mine which has controllable fresh air flow
and multiple boreholes to the surface. In addition, the
Experimental Mine stays at a consistent temperature of
roughly 13°C to 16°C (55°F to 60°F) year-round. This is
expected to be roughly halfway between the minimum and
maximum temperatures at which the LIBs will be tested.
The primary apparatuses that would be developed or
purchased include a drop test machine, a temperature/rela-
tive humidity chamber, and an immersion test apparatus.
The drop test machine will lift the tested battery to the