Extech Instruments BT100 User manual

User's Guide
Battery Capacity Tester
Model BT100

Version 2.1 7/09
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Introduction
The Battery Tester is designed for measuring the internal resistance and output voltage of
batteries including lead storage cell, nickel-cadmium battery, lithium-ion battery and nickel-
metal hydride battery.
AC four-terminal method to eliminates lead resistances and contact resistances and
yield the most accurate results.
1kHz test current with up to 10µΩresistance resolution.
Dual display simultaneously indicates the internal resistance and voltage of the
battery.
Comparator function with storage of up to 99 sets of resistance and voltage values for
battery deterioration characterization.
Pin type and alligator type 4-terminal Kelvin leads for quick and accurate resistance
measurements.
Memory capacity to store up to 999 manually stored data points or up to 9600 points
stored using interval datalogging.
RS232 PC port and Windows compatible software.
Warranty
EXTECH INSTRUMENTS CORPORATION warrants the basic instrument to be free of defects in parts and
workmanship for one year from date of shipment (a six month limited warranty applies on sensors and cables). If it
should become necessary to return the instrument for service during or beyond the warranty period, contact the
Customer Service Department at [phone] EXTENSION 210 for authorization or visit www.extech.com for
more information. A Return Authorization (RA) number must be issued before any product is returned to
Extech. The sender is responsible for shipping charges, freight, insurance and proper packaging to prevent
damage in transit. This warranty does not apply to defects resulting from action of the user such as misuse,
improper wiring, operation outside of specification, improper maintenance or repair, or unauthorized modification.
Extech specifically disclaims any implied warranties or merchantability or fitness for a specific purpose and will not
be liable for any direct, indirect, incidental or consequential damages. Extech's total liability is limited to repair or
replacement of the product. The warranty set forth above is inclusive and no other warranty, whether written or
oral, is expressed or implied.

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Specifications
Measuring method: Resistance (AC four-terminal method).
A/D conversion: Dual slope method.
Display: Dual display LCD and LEDs (comparator output).
Sampling rate: 1 set (resistance & voltage measurements)/second.
Open-Circuit terminal voltage: 3.5Vpp max.
Input over range: “OL” display.
Low battery detection: display.
Test current fault detection: “- - - -” display.
Auto power off: After approximately 30 minutes.
Zero (Relative) function: Circuit offset voltage is displayed as 0V.
Hold function: Display is held.
Beeper function: Audible output for warning and fail results (can be
turned on and off).
Comparator settings: Resistance High and Low limits and voltage
threshhold point.
Number of comparator settings: 99 sets.
Comparator output: LEDs for pass (green), warning (yellow) and fail
(red) results, audible tone for warning and fail.
Resistance
Voltage Lo IN Hi
Lo Warning Warning Fail
Hi PASS Warning Fail
Manual Data logging: 999 sets.
Continuous Data logging: 9600 sets.
Operating environment: 32 to 104°F (0
° to 40 °C) 80%RH (non-condensing)
Storage environment: 14 to 122°F (-10
° to 50 °C) 80%RH (non-condensing)
Power source: Six AA size 1.5V batteries. (AC adaptor (output
9VDC) is optional)
Maximum power consumption: 1.0VA
Continuous operating time: 7 hours approx.
Maximum altitude value usable: 2000m or less.
Size: 9.8x3.9x1.7” (250×100×45mm)
Weight: 1.1 lbs (500g) approx. (including batteries)
Accessories: Test Leads, Instruction Manual, Batteries.
Option: AC adaptor (9V DC output).

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Electrical Specifications
Conditions to guarantee accuracy:
Temperature: 23
°C ± 5 °
Humidity: 80%RH or less (non-condensing).
Zero adjustment: After zero adjustment for each range.
Resistance measurement
Temperature coefficient: (
± 0.1% rdg ± 0.5digits)/ °C
Measuring current frequency: 1KHz
± 10%
Measuring burden voltage:
1.5mVAC
Range Resolution Measurement current Accuracy
40mΩ10µΩ37.5mA approx.
400mΩ100µΩ3.75mA approx.
4Ω1mΩ375µA approx.
40Ω10mΩ37.5µA approx.
± (1% reading ± 10digits)
Voltage Measurement
Temperature coefficient (
± 0.1%rdg ± 0.5digits)/ °C
Range Resolution Accuracy
4V 1mV
40V 10mV
± (0.1% reading ± 6digits)
Maximum Input Voltage: 50VDC maximum, No AC voltage input, , 60VDC and AC
maximum between input terminals and ground.
DANGER
Do not exceed the maximum permissible input voltage to the measurement terminal. This
could result in injury or damage to the unit.

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Meter Description
1. Power button: Power on /off
2. R READ button:
Press R button to show the manual
logged readings.
Press R READ button again to stop
reading.
3. M MEMORY button:
Under the manual logging mode, the
tester stores each single set of logged
reading to the memory by pressing
M MEMORY button.
Press and hold M MEMORY button
for 2 seconds to enter continuous
logging mode. Press again to stop
logging.
4. V-RANGE button: Select the voltage
range. (4V, 40V)
5. HOLD button:
Press HOLD button to freeze or unfreeze
the displayed reading.
Press and hold HOLD button for 2
seconds to enter the interval time setting
mode for continuous data logging.
6. Ω- RANGE button: Select the resistance range. (40mΩ, 400mΩ, 4Ω, 40Ω)
7. REL button:
Press button to move the cursor to the right.
Press REL (Relative) button to zero the reading.
8. button : Press button to increase the displayed value.
9. SET button:
Press SET button to switch the comparator mode on or off.
Press and hold the SET button for 2 seconds to enter the comparator-setting mode.
Press again to store the setting in memory.
10. button: Press button to decrease the displayed value.
11. Button:
Press button to move the cursor to the left.
Press button to turn the beeper on or off.
12. RS-232 connector: PC interface connector.
13. – Input jack: For connecting with the black test lead plug.
14. + Input jack: For connecting with the red test lead plug.
15. LCD display
16. AC adaptor input

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Display Description
1. Measured resistance reading (High or Low limit of resistance on the comparator
settings)
2. Measured voltage reading (High or Low limit of voltage on the comparator settings).
3. The assigned number of comparator: 99 sets
4. The location for the manual logged data.
5. Symbols:
mΩ: Milliohm (resistance).
V: Voltage.
HOLD : Hold function.
COMP : Comparator function enabled.
: Low-Battery
:Beeper enabled
DATA R : Manual datalogging enabled.
M : Continuous datalogging enabled (Flashes when data is stored).
INTV: Interval time settings of continuous datalogging function. (1~255
seconds).
COMP.SET : Comparator settings.
HIGH: High limit setting of the comparator resistance & voltage.
LOW: Low limit setting of the comparator resistance.
LED Display Indicators
PASS (green LED): Battery complies with the high limit of comparator.
WARNING (yellow LED) Battery is beginning to deteriorate.
FAIL (red LED): Battery has failed.
These indications will appear when the High and Low comparator limits for internal resistance and
the comparator threshold value for voltage are all set.

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Basic Operation
Preparation
The following safety information must be observed to ensure maximum personal safety
during the operation of this tester.
To avoid electric shock when replacing the batteries first disconnect the leads from the
object to be measured.
Check the battery polarity carefully when inserting the batteries.
Be sure to dispose of used batteries properly.
1. Remove the battery cover.
2. Insert the batteries into the battery compartment.
WARNING
Do not attempt to measure DC voltage exceeding 50V. Do not attempt to
measure AC voltages. This could result in injury or damage to the unit.
Do not attempt to measure the voltage of a generator. This would result in an
AC voltage being applied to the voltage generating output terminals, which is
dangerous.
After measuring a high voltage battery, before continuing to measure a low
voltage battery first short the measurement leads together. This will discharge
the DC-elimination capacitor which is connected across the leads. Otherwise
an excess voltage may be applied to the low voltage battery, which is
dangerous.
Test Leads
Two sets of test leads are supplied with the meter. Both sets provide 4 terminal Kelvin
connections which eliminates lead resistance and probe contact resistance from the
measurement. Use of either the alligator or press-probe is determined by the measurement
application.

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Operation
Connect the red test lead to the “+” jack and the black test lead to the “-” jack.
1. Press Power button to turn on the tester.
2. Connect the red test probe to the positive battery terminal, and the black test probe to
the negative battery terminal.
3. Use the V-RANGE and Ω-RANGE buttons to select the desired voltage and resistance
ranges.
4. Read the battery internal resistance and DC voltage directly from the display.
Note : When the measured DC voltage or battery internal resistance value is over range,
“OL” is displayed.
When the AC test current faults, “- - - -” will be displayed.
REL Zero Adjust
The REL function zeros the selected range of resistance and voltage. The reading
displayed when the REL button is pressed will be taken as zero and will be used to
calibrate subsequent measurements.
1. Short the 4 tips of red and black test leads probe terminals.
2. Press REL button. The display shows R , then the resistance and voltage value is zero,
connect the test leads probe to the battery to be tested.
3. The zero adjustment is valid only for the currently selected range, as long as the power
remains on.

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Comparator (99 sets)
The comparator function compares the measured values with preset High and Low limit
values for internal resistance and voltage level, and determines the range that the
measurement should fall into. Then, according to the following conditions, lights the
corresponding LED, and sounds a beeper under the WARNING and FAIL cases.
Comparator Settings
1. Press and hold the “SET” button for 2 seconds, the display will show COMP.SET
indicating the comparator mode is enabled.
2. Use the or button to change the comparator number from 01 up to 99.
3. Use the V-RANGE or Ω-RANGE button to set the desired voltage and resistance
measured range.
4. Press button one time, LOW and the left two digits of the low limit resistance will be
flashing. (Use the & buttons to select the desired value.)
5. Press button one time, the right two digits of the low limit resistance will be flashing.
(Use the and buttons to select the desired value.)
6. Press button one time, HIGH and the left two digits of the high limit resistance will be
flashing. (Use the and buttons to select the desired value.)
7. Press button one time, the right two digits of the high limit resistance will be flashing.
(Use the and buttons to select the desired value.)
8. Press button one time, the left two digits of the threshold voltage will be flashing.
(Use the and buttons to select the desired value.)
9. Pressbutton one time, the right two digits of the threshold voltage will be flashing.
(Use the and buttons to select the desired value.)
10. Repeat step 2 to step 9 to set the next comparator number.
11. Press SET button again to exit from comparator setting mode.
Comparator Tables
Resistance
Voltage
Low limit resistance High limit resistance
Lo Middle Hi
WARNING
Beeper
WARNING
Beeper
FAIL
Beeper
Voltage Lo
Comparison
Value Hi Pass WARNING
Beeper
FAIL
Beeper
Comparator Start / Stop Controls
1. Press SET button to start comparator function, the COMP indication will appear on the
display, and the comparator will be operating once the measurements are taken.
2. Pressand buttons to select the desired comparator number. The selected
comparator number remains in memory even when the power is turned off.
3. Press button to set the beeper on, the indication will appear on the display,
and the beeper will sound with a WARNING or FAIL result. Press button again to
disable the beeper.
4. Press SET button again to disable the comparator function.

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Datalogging
Manual Data Logging (999 sets)
1. Log the reading one by one to the memory by pressing the MMEMORY button.
“DATA M NO XXX” will appear on the LCD for one sec. to indicate the memorized
location.
2. Press RREAD button to review the logged readings. The display will show “DATA R
NO XXX”.
3. Press The and buttons to scroll through the logged readings.
4. Press RREAD button again to stop viewing logged readings.
Continuous Data Logging
1. Press HOLD button for 2 seconds, the display will show INTV.
2. Using or button, select the desired interval time from 1 second to 255 seconds.
3. Press SET button to exit interval time setting.
4. Press MMEMORY button for 2 seconds to enter continuous logging mode, the display
will show M.
5. The Mwill flash every time a reading is stored.
6. Press MMEMORY button again to exit continuous logging mode.
7. Data stored using continuous datalogging can not be read directly on the tester’s
display, it must be downloaded to a PC using the supplied software.
Erasing Memory
When memory is full, “Full” symbol will appear on the display and logging will stop.
1. Press button to turn off the tester.
2. Press and hold the MEMORY button, then press the button. The display will indicate “CLr”
and all datalogged readings will be cleared from memory.