BRS BIM1 User manual

BIM1 / BIM2 / BTC1 / BIM300
Battery Impedance Meters
Instruction manual

Battery Impedance Meters
BRS Messtechnik GmbH
Page 2 of 36
Version 1.7 / April2015
© 2015 BRS Messtechnik GmbH
Strohberg 23
D-70180 Stuttgart
Germany
Email: [e-mail]
Tel: [phone]
File: Manual BIM-BTC-SW17.docx

Battery Impedance Meters
BRS Messtechnik GmbH
Page 3 of 36
Version 1.7 / April2015
Safety guidelines
Before use please read the instruction manual.
The device may only be used by trained technical personnel.
Even if only one cell of a battery pack is measured, if there is an er-
ror, the voltage of the whole pack or module may be shown in the
measurements.
If the test item (the battery) is attached to a charger or a converter
during the measurement, care should be taken to ensure that even if
there is an error there are no dangerous voltages above 60V across
the measurement input.
If the device is operated at high battery voltage and with a high
measurement current, the resulting loss of power causes a corre-
sponding heating of the casing. You should therefore ensure that
there is a suitable convection cooling system and that, particularly
when the ambient temperature is high, the casing can tolerate high
temperatures.
When carrying out measurements over extended periods, you should
ensure that the measurement device works in a unipolar manner, i.e.
that the test item is discharged with at least 50% of the measurement
current set. You should therefore ensure that the battery is not com-
pletely discharged.
Additional information
The device is designed to work over small voltages (less than 60V) and
is in protection class III.
Any reference to “batteries” in this instruction manual includes both primary bat-
teries as well as (rechargeable) secondary batteries (storage batteries).
Declaration of conformity
The device meets the requirements of EC Directive 2004/108/EC
(EMC Directive)
Information on environmental protection
Please dispose of the device separately from household waste at your lo-
cal collection station or recycling centre. This applies to all European Union
countries and other European countries with separate collection systems.

Battery Impedance Meters
BRS Messtechnik GmbH
Page 4 of 36
Version 1.7 / April2015
Contents
1Overview............................................................................................................... 6
1.1 Short description ...................................................................................................................... 6
1.2 Versions ................................................................................................................................... 6
1.3 Evaluation Functions................................................................................................................ 6
1.4 Selecting languages................................................................................................................. 6
2Operating preparations......................................................................................... 7
2.1 Unpacking ................................................................................................................................ 7
2.2 Installing the programs............................................................................................................. 7
2.3Positioning of the instrument.................................................................................................... 7
2.4 Connecting the measurement cable for impedance and voltage............................................. 8
2.5 Connecting the measurement cable for temperature or current (BIM2/3)............................... 9
2.6 Connecting the digital inputs/outputs....................................................................................... 9
2.7 Connecting the test item ........................................................................................................ 10
3Applications........................................................................................................ 11
4Measurement Functions..................................................................................... 12
4.1 Functional principle of the impedance measurement ............................................................ 12
4.2 Overview ................................................................................................................................ 12
4.3 Settings .................................................................................................................................. 12
4.4 Battery discharge during extended use ................................................................................. 13
5Operation............................................................................................................ 14
5.1 Measurement function at single frequency............................................................................ 14
5.2 Measurement function for spectral measurement ................................................................. 16
5.3 Measurement function capacity test (BTC1 only).................................................................. 20
5.4 Evaluation function tolerance test.......................................................................................... 22
5.5 Evaluation function Diagnosis................................................................................................ 23
5.6 Measuring and monitoring voltage......................................................................................... 25
5.7 Temperature and current measurements (BIM2, BTC1) ....................................................... 26
5.8 Single measurements ............................................................................................................ 26
5.9 Instrument configuration......................................................................................................... 27
6Data Export......................................................................................................... 28
6.1 Data export via text file (log file)............................................................................................. 28
6.2 Data export via csv files ......................................................................................................... 29
7Remote control................................................................................................... 29
8Maintenance....................................................................................................... 30
8.1 Cleaning................................................................................................................................. 30
8.2 Firmware updates .................................................................................................................. 30
8.3 Recalibration .......................................................................................................................... 30
8.4 Help........................................................................................................................................ 30

Battery Impedance Meters
BRS Messtechnik GmbH
Page 5 of 36
Version 1.7 / April2015
9RS232 Communication....................................................................................... 31
10 Technical data.............................................................................................. 32
11 Appendix...................................................................................................... 34
11.1 Recommendations for cable running ..................................................................................... 34
11.2 Recommendations for selecting frequencies......................................................................... 34

1 Overview
1.1 Short description
The BIM1/BIM2/BTC1/BIM300 are economical, easy to
operate and compact battery impedance measuring in-
struments.
They offer functions of a battery tester, of a battery ana-
lyser and a capacity tester and enable the quick test of
batteries and accumulators.
They are connected in parallel to the battery terminals
and measure the complex battery impedance and voltage of cells or modules inde-
pendently of the battery technology. Some versions offer additional temperature and
current measurements.
The measurement values are provided in an electrically isolated manner via a USB
communication interface. The device is operated with a graphical user interface
(GUI) and the results are shown on this interface. Alternatively, there is a program-
ming interface for remote control.
1.2 Versions
Measurement Functions
BIM1
BIM2
BTC1
BIM300
Impedance
1µΩ…1Ω
1µΩ…1Ω
1µΩ…1Ω
1mΩ…500Ω
Frequency range
1-1000Hz
0,1-1000Hz
0,1-1000Hz
0,1-1000Hz
Voltage
0…60V
0…60V
0…60V
0…60V
Temperature via ext. PT1000
----
yes
yes
----
Current via ext. current clamp
----
yes
yes
----
Capacity (current ≤2A)
----
----
yes
----
Each version requires compliant firmware and PC software.
1.3 Evaluation Functions
Graphical presentation of spectral impedance as Nyquist chart
Approximation of model parameters (substitute values)
Calculation of battery states (diagnostics) by means of reference values
Tolerance analysis for production testing by comparison with reference values
1.4 Selecting languages
The language can be changed at any time in the menu
“extras”.

Battery Impedance Meters
BRS Messtechnik GmbH
Page 7 of 36
Version 1.7 / April2015
2 Operating preparations
2.1 Unpacking
Please check to ensure that the delivery is complete:
BIM measurement instrument with adapters for digital inputs/outputs
Operating software on CD-ROM: GUI as exe, USB driver
English instruction manual: printed and as a PDF on the CD-ROM
USB connection cable 1.8m
2 pcs of measurement cables (1m each): for impedance and for temperature
2.2 Installing the programs
Copy the control program (BIMGIU.exe) to a suitable folder, e.g. in the Programs
folder.
Connect the measurement device to the computer using the USB cable. The operat-
ing system will find the new device and will ask for information about the driver. Man-
ually select the “FTDI” folder in the CD drive and confirm by clicking on “OK”
1
. If you
have an internet connection, you can also download the driver directly.
Start the graphic user interface by double clicking on BIMGIUI.exe. In the top right
corner of the GUI, the HW-Link status will be shown. The soft-
ware automatically searches for available interfaces. As soon as
the communication is established, the colour changes into
green, and the device is ready for use
2
.
The USB cable is used for both data communication and providing the device with a
5V voltage and a maximum power supply of 100mA.
2.3 Positioning of the instrument
A power of up to 6W caused by the measurement current can occur
in the device, which has to be dissipated through the casing. Regard-
less of its orientation, the device should be set up so that sufficient
convection cooling is possible.
1
If that does not work, please use the device manager. Look for “unkown device”. With right mouse
click you will come to “update driver software”.
2
If the device is not found, remove and attach the USB cable again.

Battery Impedance Meters
BRS Messtechnik GmbH
Page 8 of 36
Version 1.7 / April2015
2.4 Connecting the measurement cable for impedance and voltage
On the left-hand front panel there is a measure-
ment socket, to which the measurement cable is
attached. The plug has a push-pull mechanism,
which means it is pushed in until it locks and
pulled out of the plug casing to remove.
There are several types of measurement cable for connecting the test item:
a) MK-S: Standard variant
This measurement cable has two Kelvin clips, which are connected to the two poles
of the test item. It is simple to use and produces good results for most cells.
Meaning
Colour of the Kelvin clips
Current connection I+
Voltage connection U+
red; the two connections are
guided separately to the collet
jaws
Current connection I-
Voltage connection U-
black; the two connections are
guided separately to the collet
jaws
b) MK-U: Universal variant
For very low ohmic cells (>10Ah, <1mOhm), the use of the cable with four crocodile
clips is recommended, because it can be connected more precisely, but it is also a
little more awkward to use.
Meaning
Colour of the crocodile clips
Current connection I+
Current connection I-
red (at the + pole)
black (at the –pole)
Voltage connection U+
Voltage connection U-
green (at the + pole)
blue (at the –pole)
c) MK-K: variant for cable lugs
For very low ohmic cells with threaded bolts or female threads. The two lugs per pole
are isolated against each other with an insulating bushing. Available for threads M6,
M8, M10.

Battery Impedance Meters
BRS Messtechnik GmbH
Page 9 of 36
Version 1.7 / April2015
Meaning
Colour of the lugs
Current connection I+
Current connection I-
red (at the + pole)
black (at the –pole)
Voltage connection U+
Voltage connection U-
green (at the + pole)
blue (at the –pole)
d) MK-G: Variant for threaded holes
For the temporary connection to very low ohmic cells with threaded holes. The
probes are inserted into the holes and retained by springs. Available for threads M6,
M8, M12, M14 and thread depths between 12mm and 24mm.
Meaning
Colour of the plugs
Current connection I+
Current connection I-
red (male, at the + pole)
black (male, at the –pole)
Voltage connection U+
Voltage connection U-
green (female, at the + pole)
blue (female, at the –pole)
If you need special measurement cables, we can provide these –please ask.
2.5 Connecting the measurement cable for temperature or current (BIM2/3)
For temperature measurement an external RTD (PT1000) can be connected to the
second input at the front side. The temperature sensor is connected to the enclosed
cable. The sensor must be galvanically isolated.
Alternatively, a current sensor (current clamp) can be connected to this plug. The
sensor connects to other pins of the plug, so you need a different cable –please ask.
2.6 Connecting the digital inputs/outputs
The digital inputs/outputs are situated on the opposite
front panel.
The digital inputs/outputs are connected using a two-
pole phoenix plug. The external parts to be attached
have the manufacturer designation FK-MC0,5/2-ST-
2,5 and are enclosed. Wires can be clipped into these
plugs –push the orange clamping lugs downwards with a sharp object and guide the
wire into the hole above it.
The two LEDs indicate the status: green means logically one.

Battery Impedance Meters
BRS Messtechnik GmbH
Page 10 of 36
Version 1.7 / April2015
2.7 Connecting the test item
The impedance measurement device works according to the four-conductor principle
(Kelvin connection), and therefore has four connections for measuring impedance:
two connections for feeding in the current (I+ and I-)
and two connections for measuring the voltage (U+
and U-). They are only brought together on the test
item (battery) and connected in pairs (I+ and U+
with the positive pole, I- and U- with the negative
pole).
If the measurement cable is used with the two Kel-
vin clips, this happens automatically because each
clip contains both a current and a voltage connec-
tion.
When using the measurement cable with the four
crocodile clips, two clips must be attached to each
battery pole.
The non-terminated cable provides the greatest degree of freedom, such as the con-
nection of test buttons, screwed together cable lugs or a solder connection. This
sometimes gives more reproducible results
When connecting the measurement conductor, pay attention to the
voltage potential. The device has polarity protection, but the (auto-
matically reset) protection could be activated.
Take care that no high voltages above 60V occur.
Please note that if there is an error when measuring cells in the bat-
tery module, the overall voltage of the battery module may be pre-
sent at the measurement inputs.
Please note that the measurement device discharges the battery and
can therefore completely discharge the battery if it is left to run with-
out any control.
The lower the impedance to be measured, the higher the requirements for the meas-
urement connection. For very low impedances (<1mΩ), special connection might be
advisable - please inquire.
Recommendations for proper wiring can be found in section 10.1.
Battery
+
-
I+ I-
U+ U-

Battery Impedance Meters
BRS Messtechnik GmbH
Page 11 of 36
Version 1.7 / April2015
3 Applications
Overview
Measure-
ment Para-
meter
Battery Property
Develop-
ment
Produc-
tion
Mainte-
nance
Service
Voltage
State of charge
(Li-Ion, Lead)




AC-
Resistance
Ageing (SoH)




DC-
Resistance
Operational behavi-
our



Nyquist plot
(Spectral
impedance)
Operational behav-
iour, Beschädigun-
gen, Modellparame-
ter

()
()
Application
Charac-
terization
Selection
Qualificati-
on and
exchange
Diagnosis
Reference parameters
tbd
batch of
cells
adjecent
cells
Data sheet
or initial
measure-
ment
First steps, typical approach
It is good practise to take the following approach for characterising batteries:
Measurement of the open circuit voltage (OCV). The acceptable range can be
taken from the specifications or from the discharge curve.
The menu “Diagnosis” uses typical values which are stored in a spreadsheet,
from which the SoC can be derived.
Measurement of the AC resistance (RAC, ESR). In the menu “Single impedance”
choose the standard frequency 1kHz and compare it with the specification.
The function „Diagnosis“ uses this parameter to estimate the ageing (SoH) by
comparing this value with a reference value, which has to be defined once.
For determining the operational behavior measure the DC impedance at 0,5Hz
and compare it with a reference value from a new battery.
For deeper analysis measure the Nyquist plot and compare it with the plot of a new
battery.

Battery Impedance Meters
BRS Messtechnik GmbH
Page 12 of 36
Version 1.7 / April2015
4 Measurement Functions
4.1 Functional principle of the impedance measurement
The measurement device loads the battery with
an alternating current (IAC) which is considerably
smaller than the load current, and measures the re-
sulting voltage (UAC), which is in the mV range.
The measurement of alternating voltage is carried
out selectively and synchronously, with the results
by real part and imaginary part. Dividing the alternat-
ing voltage by the alternating current yields the complex impedance ZAC. The real
part represents the ohmic components, the imaginary part represents the capacita-
tive (or inductive) components. A negative imaginary part means capacity, a positive
part means inductance.
4.2 Overview
The device is operated using a graphical user interface (GUI). Settings can be ad-
justed and the results shown using this interface.
All setting and results can also be remote controlled using a proprietary communica-
tion protocol.
4.3 Settings
a) Measurement range
The measurement ranges depend on the instrument version:
1mΩ
3mΩ
10mΩ
30mΩ
100mΩ
300mΩ
1Ω
3Ω
10Ω
30Ω
100Ω
300Ω
BIM1
BIM2
BTC1
BIM300
3
AC current
(mAss)
2000
1000
200
100
20
10
5
2
1
0,2
0,1
0,05
DC current
(mA)
1000
500
100
50
10
5
2,5
1
0,5
0,1
0,05
0,025
If the expected impedance is known, then the closest range can be set. If not, it is
best to start at the highest level (1Ω) and reduce it as necessary.
3
The 300Ω range can be used up to 500Ω.
UAC
IAC

Battery Impedance Meters
BRS Messtechnik GmbH
Page 13 of 36
Version 1.7 / April2015
Since the impedance decreases with the frequency, the measurement range should
be oriented towards the lowest frequency to be measured.
The measurement current is set automatically, depending on the range; a lower
range has a higher current.
During impedance measurements the battery is loaded and the re-
sulting power has to be dissipated within the instrument. This power
has to be lower than 6W. Thus please note the following derating for
the battery voltages:
Measurement range
Average current
Max. Voltage
3mΩ
500mA
12V
1mΩ
1000mA
6V
b) Measurement frequency
The measurement frequency can be set between 0,1Hz (1Hz with BIM1) and 1kHz in
quasi-logarithmic step with 6 values per decade.
The lower the frequency, the longer the measurement time. It is therefore sensible to
work with as high a frequency as possible.
4.4 Battery discharge during extended use
When taking measurements over an extended period, please note that the meas-
urement device works in a unipolar manner. This means that the test item will be dis-
charged with 50% of the measurement current.
Please take care to ensure that the battery is not completely dis-
charged. You can use the integrated voltage monitor for this.
Please be aware that even when disconnected the input resistance of
the voltage measurement of around 50 kΩ lies in parallel to the bat-
tery clips. You should therefore completely disconnect the measurement device
when no measurements are being carried out over an extended period.

Battery Impedance Meters
BRS Messtechnik GmbH
Page 14 of 36
Version 1.7 / April2015
5 Operation
5.1 Measurement function at single frequency
Select the “single impedance” operation by clicking on the relevant tab.
First select the measurement range; the measurement current will automatically ad-
justed. Then choose the measuring frequency from a set of 24 predefined frequen-
cies.
The impedance Z is displayed in two forms: by real part and imaginary part and by
magnitude and phase. The real part represents the active resistance component and
the imaginary part shows the inductive or capacitative blind part. Positive imaginary
parts show inductance, negative imaginary parts show capacities. The frequency plot
is called Nyquist chart.
An alternative representation is in polar form as magnitude an phase. The frequency
plot of these 2 variables is a Bode plot.

Battery Impedance Meters
BRS Messtechnik GmbH
Page 15 of 36
Version 1.7 / April2015
Relations in the complex plane:
Exceeding the range
If the input signal is above the measurement window, e.g. due to overdrive or by a
test item not being connected, the message measurement connection? will be shown
beneath the results display.
If the result is not valid, this will be indicated by a bar (---).
Notes on measurement accuracy
For high measurement frequencies, the inductance of the test item becomes notice-
able. Example: a good reference resistor shows an inductance of <10nH according to
the specification. For a frequency of 1kHz, the inductive impedance (measured as an
imaginary part) is 0.063 mΩ.
Real axis
Imaginary axis
Real part of Z = R
Imaginary part of Z = C
Phase of Z

Battery Impedance Meters
BRS Messtechnik GmbH
Page 16 of 36
Version 1.7 / April2015
5.2 Measurement function for spectral measurement
In the “spectrum” measurement type, there are periodic frequency scans, i.e. all
measurement frequencies, starting with the highest frequency of 1kHz are measured
one after the other
4
.
The results are shown as a frequency response plot by real and imaginary parts with
the frequency as a parameter. This display is also known as a Nyquist plot. The real
part (ohmic component) is plotted horizontally; the imaginary part is on the vertical
axis. It is customary for the negative imaginary axis to be shown vertically so that the
capacities (negative imaginary part) can be shown in the first quadrant, as this gives
a better overview.
The impedance with the lowest value and highest frequency is on the left-hand side
of the Nyquist curve; the impedance with the highest value and lowest frequency is
on the right-hand side of the curve.
New values are added to the diagram, and the older values are overwritten. The
“clear graphic” button deletes all of the values.
The display area can be changed using the directional arrows independently of the
measurement range. You can move the graphic horizontally by clicking into the
graphic with the left mouse button and holding the button down.
4
This type of measurement is also known as EIS (Electric Impedance Spectroscopy).
actual frequency
Zoom function

Battery Impedance Meters
BRS Messtechnik GmbH
Page 17 of 36
Version 1.7 / April2015
If a spectral measurement is started as a sin-
gle scan, the ongoing measurement is indi-
cated by a red bar below. It changes to green
if the measurement cycle is finished.
Frequency grid
The frequency grid can be changed in terms of stop
frequency (1Hz or 0,1Hz) as well as step size (3 values
per decade or 6 values per decade).
Thus speed and resolution can be adapted:
Frequency-Indices
Frequency/Hz
6/D and 0,1Hz
6/D and 1Hz
3/D and 0,1Hz
3/D and 1Hz
1000
1
1
1
1
500
2
2
2
2
333
3
3
250
4
4
3
3
143
5
5
100
6
6
4
4
71,4
7
7
45,5
8
8
5
5
33,3
9
9
21,7
10
10
6
6
15,2
11
11
10,0
12
12
7
7
6,8
13
13
4,7
14
14
8
8
3,3
15
15
2,2
16
16
9
9
1,5
17
17
1
18
18
10
10
0,68
19
0,47
20
11
0,33
21
0,22
22
12
0,15
23
0,10
24
13
Meas. time
ca. 3 min
ca. 22 sec
ca. 2 min
ca. 13 sec

Battery Impedance Meters
BRS Messtechnik GmbH
Page 18 of 36
Version 1.7 / April2015
Approximation
The “approximation” button
adds a blue approximation
curve
5
between the two se-
lectable measurement
points. The two points can
be selected in settings by
clicking on “approximation”
as a frequency index.
The two frequency indices
are pre-set to the first
measurement point (e.g. 1:
1 kHz) and to the last meas-
urement point (e.g. 9: 2.2
Hz), but they can also be
changed. Enter the desired frequency index in the left-hand field and confirm with =>.
The parameters Rs, Rpand Cpof the simplified
Randles equivalent circuit diagram are calculated with
the help of the approximation and the results are
shown to the left of the graphic.
In some cases, two half curves can be identified
(which represent one electrode each). These
two half curves can be separately approximated
in such a way that a third frequency index is de-
termined in the middle, i.e. the x is replaced with
a number. This represents the cross-over be-
tween the two approximation curves.
5
The approximation is done using the ZARC model (tilted arch impedance)

Battery Impedance Meters
BRS Messtechnik GmbH
Page 19 of 36
Version 1.7 / April2015
Reference curves
The measured Nyquist curves can be saved and
displayed for comparison. They also serve as
must curves in the tolerance test.
After completion of a measurement cycle, the re-
sults are saved by clicking “store measurement”
6
.
If there are still no complete location curves, a
message will inform you of this. If there is a com-
plete location curve, another window will open
where you can add a name and a note to the lo-
cation curve to be saved. The file is saved when
you click OK, which will save the most recent
complete point sequence.
To show the reference curves:
First click the “on/off” button, and then click the “settings” button.
The available curves are shown in the window
which then opens (see left).
You can see a preview of this by simply marking
the desired curve in this field.
The relevant reference curve (in red) is blended in
with the associated notes (temporarily).
The reference curve can be permanently blended
in by clicking on the “=>” button.
Permanent reference curves are shown in or-
ange/yellow and the notes are not shown.
Permanent reference curves can be selected again later if you mark them as “in use”
in the field.
The values can be shown numerically in a notepad file by clicking on the “plot data”
button.
6
They are stored in the file „ RefPlot.txt”

Battery Impedance Meters
BRS Messtechnik GmbH
Page 20 of 36
Version 1.7 / April2015
5.3 Measurement function capacity test (BTC1 only)
The battery capacity is measured by discharging a fully charged battery until the
specified cut-off voltage is reached. Integrating the current over time results in
charge.
The battery parameters (nominal capacity, discharging cut-off voltage) and the dis-
charging current are entered in the white area and activated with the button “take
over”.
It can be selected wether a full discharge to the final voltage is conducted; alterna-
tively the battery can be discharged by a selectable value.
The measurement is initiated by pressing the “start” button. The remaining time will
be indicated both as value and as bar graph. The display shows the actual discharge
current, the actual voltage and the actual accumulated charge.
If a fully charged battery is discharged until the final (cut-off) voltage, the accumulat-
ed charge represents the “measured capacity” of the battery.
During the discharging process no changes of parameters are possible. This is only
possible by interrupting the process by pressing the button “break”. The discharge is
halted and continued by the respective button.