Megger BITE2 Specifications

BITE

Battery Impedance Test Equipment

BITE®2 and BITE2P

Battery Impedance Test Equipment

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Determines condition of lead-acid and

NiCd cells up to 7000 Ah

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On-board Pass/Warning/Fail indications

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Robust, repeatable instruments

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On-line testing

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Checks charger condition by measuring

BITE2P

BITE2

ac ripple current

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Includes PowerDB LITE Software

®

2 and BITE2P

DESCRIPTION

The BITE2 and BITE2P Battery Impedance Test Equipment
determine the condition of lead-acid and nickel-cadmium cells
up to 7000 Ah. An advanced feature set has been developed
that includes Pass/Warning/Fail calculations based on a user­entered baseline value, advanced printing functions and more.
The case of the BITE2P consists of both the transmitter and a
carrying case for all of the standard accessories and some of
the optional accessories, in an all-in-one unit. The BITE2 and
its accessories fit into a sturdy canvas case with a shoulder
strap.

The instruments work by applying a test signal across the
battery string while on-line, then calculates impedance based
on simultaneous measurements of current and resulting
voltage drop of each cell/jar. They also measure dc voltage
and interconnection (strap) resistance to help determine the
overall condition of the entire battery string’s electrical path
from terminal plate to terminal plate.

In addition, the BITE2 and BITE2P measure ac ripple current
which, if too high and over an extended period of time, can
damage the battery by heating it. (An increase of battery
temperature by 18ºF/10ºC will halve the life of lead-acid
batteries.) Battery manufacturers generally recommend a limit
of 5A of ac ripple current for every 100 Ah of battery capacity.
The first measurement that the instruments take is ac ripple
current which should be trended.

The BITE2 and BITE2P receiver stores the readings in its
internal memory. These measurements, along with other
maintenance data such as ambient and pilot cell temperatures
and ac ripple current, assist in determining the overall
condition of battery systems. Megger recommends that
impedance measurements with the
BITE2 or BITE2P be made part of a battery maintenance
program with readings taken and recorded semiannually for
flooded batteries and quarterly for VRLA.

Unlike load cycle testing that involves substantial downtime
and repeated discharges, using the instruments require no
battery discharge, nor do they stress the battery in any way

compared to other techniques. With a test time of less than 15
seconds for each cell and intercell connector, one person can
easily, quickly, and precisely measure internal cell impedance,
dc terminal voltage and intercell connection resistance
without taking the battery system off line and evaluate charger
condition also.

Naturally, everything you need to perform these tests is
included with the basic instruments. There is a full line of
optional accessories to enhance the capabilities of the BITE2
and BITE2P. Both have the ability to download to a PC for
data interpretation and to PowerDB, Megger’s battery database
management software. Additionally, the BITE2P has a built-in
printer to review the active test and also to leave a hard copy
record at the site

.

Receiver

The battery-operated receiver incorporates the potential leads,
clamp-on current sensor, and data storage capabilities. It stores
more than 2000 sets of data (cell impedance, cell voltage and
interconnecting strap resistance, date and time stamps) in up
to 300 tests. It also allows for printing the active test for easy
review and retest. Selective printing of any test and deleting
oldest tests are now included features to maintain in memory
the most critical tests.

At any time while performing a test, the operator can review
the current test results by using arrow keys and scrolling back
through the active test screen. The operator can also print the
active test using the BITE2P transmitter printer. If needed, the
operator can retest any of the cells and straps in the current
test. Stored data can also be downloaded via the RS-232
connector directly to a personal computer or the BITE2P
transmitter printer.

One additional feature of the receiver is that if you are called
away while in the middle of the test, simply shut down the
instrument and it will remember where you left off in the test.

The clamp-on current sensor is connected to the receiver
during testing and clamped around a convenient intertier or
intercell connection within the loop created by the transmitter’s

BITE®2 and BITE2P

Circuit

Battery Impedance Test Equipment

current source leads and the battery string. If the intercell or
intertier connection consists of more cables than the diameter
of the clamp-on current sensor can encompass, the receiver
has a split-strap function.

There are optional RopeCTs

TM

available for large buss work.
With the optional bar-code wand, additional information such
as location ID, user ID, ambient and pilot cell temperatures
can be recorded and stored. There is space on the printout to
enter specific gravity readings.

Battery Analysis Report

Location ID:

User ID: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Notes: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Ambient Temp: Pilot Temp:

Ripple Current: .01A Test AC Current: 9.8 A

Multiplier: 1 B/W/F: 11.00 mW/20%/40%

Cell Sp.Gr. Zb mW P/W/F % RS mW Volts DC Time

001 12.09 P 09 0.412 13.52 11:13

002 12.22 P 11 0.407 13.34 11:14

003 14.02 W 27 0.405 13.59 11:14

004 14.54 W 32 0.403 13.48 11:15

005 12.60 P 14 0.042 13.27 11:16

006 12.09 P 09 0.405 13.38 11:17

Minimum Average Maximum

12.09 12.93 14.54

-10 0 10 20 30
001

002

003

004

005

006

Figure 1. Sample battery analysis report

05-SEP-2000

Cell Impedance Summary

Percent Deviation from Average

Transmitter

The transmitter provides the capacitively coupled ac test signal
to avoid transients on the dc buss and applies it to the cells
under test via the source leads. Both the BITE2 and BITE2P
transmitters have an LCD and built-in receiver charger, while
the BITE2P transmitter features a built-in printer.

Data, measured and stored in the receiver can be exported to
a PC. It can also be printed to the BITE2P transmitter printer
where it can be reviewed. Figure 1 shows a sample printout of
a full battery analysis report.

APPLICATIONS

A battery’s internal impedance increases with decreasing
capacity due to various conditions such as age, ambient
temperature, discharge history, etc. See Figure 2. Both the
BITE2 and BITE2P measure impedance values and dc voltage
for lead-acid and nickel-cadmium cells up to 7000 Ah capacity.

Impedance finds electrical path problems due to plate
sulphation, post-seal corrosion, dry-out, and poor intracell
and intercell connections. This information lets the operator
determine maintenance needs such as:

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Cell replacement criteria based on impedance trends.

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Jumpering out a cell or two.

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Clean and/or retorque intercell connectors.

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Shorten the maintenance interval, etc.

Typical installations that can be tested using the BITE2
and BITE2P include:

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Electrical power generation plants.

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Substations: utility, railroad, industrial

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Telecommunications facilities: CO, Wireline, Wireless, MTSO

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UPS systems

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Railroad: Signals and Communications, substation

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Aircraft power supplies

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Marine, military

FEATURES AND BENEFITS

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On-line testing requiring no downtime.

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Enhanced printing and memory functions.

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Calculates impedance automatically and stores results

for on-site review.

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Requires no battery discharge.

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Receiver can download stored data to PowerDB software for

quick, easy analysis.

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Reduced test time: less than 3 seconds for each cell.

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Measures impedance and dc voltage values for all lead-acid

and nickel-cadmium cells up to 7000 Ah.

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Stores more than 2000 sets of readings in up to

300 tests.

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Checks charger condition by measuring ac ripple current.

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PowerDB LITE allows data to be stored and allows custom

reporting. (ideal for NERC & FERC requirements)

Test Procedure

The BITE2 and BITE2P work by applying a capacitively
coupled ac test signal across the battery string while on­line. The receiver and potential probe are placed at the cell
terminals to measure the signal and resulting voltage drop
for each cell/jar. During each measurement, impedance is
calculated following Ohm’s Law, displayed on the LCD and
stored. The instruments also measure, display and record
dc voltage and interconnection (strap) resistance to help
determine the overall condition of the entire battery string’s
electrical path from terminal plate to terminal plate. The also
measure ac ripple current, a charger parameter.

The BITE2 and BITE2P receiver stores the readings in its
internal memory. These measurements, along with other
maintenance data such as ambient and pilot cell temperatures
and ac ripple current, assist in determining the overall
condition of battery systems. Figure 2 shows a typical test
setup.

STRAP

CURRENT SOURCE

LEAD

CELL

RED

TRANSMITTER

LINE

VOLTAGE

CURRENT SOURCE

LEAD

BLACK

Located

in Battery

Figure 2. A typical test setup

“CT”