Nickel Cadmium Batteries
Technical Handbook ‘02/‘03
PDF File Technical Handbook
Copyright 2002 Matsushita Battery Industrial Co., Ltd. All rights Reserved. No part of this technical
handbook pdf file may be changed, altered, reproduced in any form or by any means without the
prior written permission of Matsushita Battery Industrial Co., Ltd.
NOTICE TO READERS
It is the responsibility of each user to ensure that each battery application system is adequately
designed safe and compatible with all conditions encountered during use, and in conformance
with existing standards and requirements. Any circuits contained herein are illustrative only
and each user must ensure that each circuit is safe and otherwise completely appropriate for
the desired application.
This literature contains information concerning cells and batteries manufactured by Matsushita
Battery Industrial Co., Ltd. This information is generally descriptive only and is not intended to
make or imply any representation guarantee or warranty with respect to any cells and batteries.
Cell and battery designs are subject to modification without notice. All descriptions and
warranties are solely as contained in formal offers to sell or quotations made by Matsushita
Battery Industrial Co., Ltd., Panasonic Sales Companies and Panasonic Agencies.
NICKEL CADMIUM BATTERIES: TABLE OF CONTENTS
Nickel Cadmium Batteries: Table of Contents
Precautions for Designing Devices with Ni-Cd Batteries .............. 2
Rechargeable Ni-Cd Batteries ........................................................... 6
•
Overview
•
Construction
•
Battery Reactions
•
Five Main Characteristics
Charge Methods for Ni-Cd Batteries .............................................. 10
Summary Specification Tables .........................................................24
Standard “N” Type ............................................................................26
High Capacity “S” Type ....................................................................28
Rapid Charge “R” Type ....................................................................30
High Rate Discharge and Rapid Charge “P” Type ........................32
Trickle Charge “H” and “K” Type ...................................................34
Battery Selection ...............................................................................37
•
Charts
Individual Data Sheets ......................................................................40
•
Specifications
•
Dimensions
•
Characteristics
Battery Packs .....................................................................................80
Transportation and Disposal Guidelines .......................................83
Glossary of Terms for Ni-Cd Batteries ............................................84
NICKEL CADMIUM HANDBOOK, PAGE 1
FEBRUARY 2002
PRECAUTIONS FOR DESIGNING DEVICES WITH NI-CD BATTERIES
In order to take full advantage of the properties of Ni-
Cd batteries and also to prevent problems due to
improper use, please note the following points during
the use and design of battery operated products.
Underlined sections indicate information
that is especially important
1. Charging
1.1 Charging temperature
•
Charge batteries within an ambient temperature
range of 0°C to 45°C.
•
Ambient temperature during charging affects
charging efficiency. As charging efficiency is best
within a temperature range of 10°C to 30°C,
whenever possible place the charger (battery
pack) in a location within this temperature range.
•
At temperatures below 0°C the gas absorption
reaction is not adequate, causing gas pressure
inside the battery to rise, which can activate the
safety vent and lead to leakage of alkaline gas
and deterioration in battery performance.
•
Charging efficiency drops at temperatures above
40°C. This can disrupt full charging and lead to
deterioration in performance and battery leakage.
1.2 Parallel charging of batteries
•
Sufficient care must be taken during the design
of the charger when charging batteries con-
nected in parallel.
Consult Panasonic when parallel charging is
required.
1.3 Reverse charging
•
Never attempt reverse charging.
Charging with polarity reversed can cause a
reversal in battery polarity causing gas pressure
inside the battery to rise, which can activate the
safety vent, lead to alkaline electrolyte leakage,
rapid deterioration in battery performance,
battery swelling or battery rupture.
1.4 Overcharging
•
Avoid overcharging. Repeated overcharging can
lead to deterioration in battery performance.
(“Overcharging” means charging a battery when
it is already fully charged.)
1.5 Rapid Charging
•
To charge batteries rapidly, use the specified
charger (or charging method recommended by
Panasonic) and follow the correct procedures.
1.6 Trickle charging (continuous charging)
•
Carry out trickle charge by applying the current
of 0.02 to 0.05 CmA. The correct current value
is determined depending on the features and
purpose of the equipment.
•
Note : “CmA”
During charging and discharging, CmA is a
value indicating current and expressed as a
multiple of nominal capacity. Substitute “C” with
the battery’s nominal capacity when calculating.
For example, for a l500mAh battery of
0.033CmA, this value is equal to 1/30
×
1500, or
roughly 50mA.
2. Discharging
2.1 Discharge temperature
•
Discharge batteries within an ambient tempera-
ture range of -20°C to +65°C.
•
Discharge current level (i.e. the current at
which a battery is discharged) affects discharg-
ing efficiency. Discharging efficiency is good
within a current range of 0.1 CmA to 0.5 CmA.
•
Discharge capacity drops at temperatures
below -20°C or above +65°C. Such decreases
in discharge capacity can lead to deterioration in
battery performance.
2.2 Overdischarge
•
Since overdischarging damages the battery
characteristics, do not forget to turn off the
switch when discharging, and do not leave the
battery connected to the equipment for long
periods of time. Also, avoid shipping the battery
installed in the equipment.
2.3 High-current discharging
•
As high-current discharging can lead to heat
generation and decreased discharging effi-
ciency, consult Panasonic before attempting
continuous discharging or pulse discharging at
currents larger than 2 CmA.
NICKEL CADMIUM HANDBOOK, PAGE 2
FEBRUARY 2002
PRECAUTIONS FOR DESIGNING DEVICES WITH NI-CD BATTERIES-(CONT.)
3. Storage
3.1 Storage temperature and humidity (short-term)
•
Store batteries in a dry location with low humidity,
no corrosive gases, and at a temperature range
of -20°C to +45°C.
•
Storing batteries in a location where humidity is
extremely high or where temperatures fall below
-20°C or rise above +45°C can lead to the
rusting of metallic parts and battery leakage due
to expansion or contraction in parts composed of
organic materials.
3.2 Long-term storage (2 year, -20°C to +35°C)
•
Because long-term storage can accelerate
battery self-discharge and lead to the deactiva-
tion of reactants, locations where the tempera-
ture ranges between +10°C and +30°C are
suitable for long-term storage.
•
When charging for the first time after long-term
storage, deactivation of reactants may lead to
increased battery voltage and decreased battery
capacity. Restore such batteries to original
performance by repeating several cycles of
charging and discharging.
•
When storing batteries for more than 1 year,
charge at least once a year to prevent leakage
and deterioration in performance due to self-
discharging. When using a rapid voltage detec-
tion type battery charger carry out charge and
discharge at least once every 6 months.
4. Service Life of Batteries
4.1 Cycle life
•
Batteries used under proper conditions of charg-
ing and discharging can be used 500 cycles or
more.
Significantly reduced service time in spite of
proper charging means that the life of the battery
has been exceeded.
Also, at the end of service life, an unusual in-
crease in internal resistance, or an internal short-
circuit failure may occur. Chargers and charging
circuits should therefore be designed to ensure
safety in the event of heat generated upon battery
failure at the end of service life.
Please contact Panasonic if you have any ques-
tions.
4.2 Service life with long-term use
•
Because batteries are chemical products involv-
ing internal chemical reactions, performance
deteriorates not only with use but also during
prolonged storage.
Normally, a battery will last 3 to 5 years if used
under proper conditions and not overcharged or
overdischarged.
However, failure to satisfy conditions concerning
charging, discharging, temperature and other
factors during actual use can lead to shortened
life (or cycle life) damage to products and dete-
rioration in performance due to leakage and
shortened service life.
5. Design of Products Which Use Batteries
5.1 Connecting batteries and products
•
Never solder a lead wire and other connecting
materials directly to the battery, as doing so will
damage the battery’s internal safety vent, separa-
tor, and other parts made of organic materials.
To connect a battery to a product, spot-weld a tab
made of nickel or nickel-plated steel to the
battery’s terminal strip, then solder a lead wire to
the tab.
Perform soldering in as short a time as possible.
•
Use caution in applying pressure to the terminals
in cases where the battery pack can be sepa-
rated from the equipment.
•
When rapid charging using the voltage detection
method with a large current (1It or more), or when
leaving the battery installed in the equipment, be
sure to follow connecting the precaution listed
above. Even for other uses, if connecting the
precaution listed above is used as much as
possible, contact defects in the connection
process can be reduced.
5.2 Material for terminals in products using the
batteries
•
Because small amounts of alkaline electrolyte
can leak out from the battery seal during extended
use or when the safety vent is activated during
improper use, use a highly alkaline-resistant
material for a product’s contact terminals in order
to avoid problems due to corrosion.
High Alkaline-resistant Metals
Nickel, stainless steel, nickel-
plated steel, etc.
Low Alkaline-resistant Metals
Tin, aluminum, zinc, copper,
brass, etc.
(Note that stainless steel generally results in higher contact resistance.)
NICKEL CADMIUM HANDBOOK, PAGE 3
FEBRUARY 2002
PRECAUTIONS FOR DESIGNING DEVICES WITH NI-CD BATTERIES-(CONT.)
5.3 Temperature related to the position of batteries in
products
•
Excessively high temperatures (i.e. higher than
45°C) can cause alkaline electrolyte to leak out
from the battery, thus damaging the product and
shorten battery life by causing deterioration in the
separator or other battery parts. Install batteries
far from heat-generating parts of product. The
best battery position is a battery compartment
that is composed of an alkaline-resistant material
which isolates the batteries from the product’s
circuitry. This prevents damage caused by a
slight leakage of alkaline electrolyte from the
battery. Be careful particularly when trickle
charging is carried out (for continuous charging).
5.4 Discharge end voltage
•
Overdischarge and reverse charge of the battery
deteriorate battery characteristics. This can be
caused by several actions, such as forgetting to
turn off the power. Installing an overdischarge
cutoff circuit is recommended in order to avoid
overdischarge and reverse charge.
•
The discharge end voltage is determined by the
formula given below.
6.2 Short-circuiting
•
Never attempt to short-circuit a battery. Doing
so can damage the product and generate heat
that can cause burns.
6.3 Throwing batteries into a fire or water
•
Disposing of a battery in fire can cause the
battery to rupture. Also avoid placing batteries in
water, as this causes batteries to cease to
function.
6.4 Soldering
•
Never solder anything directly to a battery. This
can destroy the safety features of the battery by
damaging the safety vent inside the cap.
6.5 Inserting the batteries with their polarities re-
versed
•
Never insert a battery with the positive and
negative poles reversed, as this can cause the
battery to swell or rupture.
6.6 Overcharging at high currents and reverse
charging
•
Never reverse charge or overcharge with high
currents (i.e. higher than rated). Doing so causes
rapid gas generation and increased gas pres-
sure, thus causing batteries to swell or rupture.
•
Charging with an unspecified charger or specified
charger that has been modified can cause
batteries to swell or rupture. Be sure to indicate
this safety warning clearly in all operating instruc-
tions as a handling restriction for ensuring safety.
6.7 Installation in equipment (with an airtight battery
compartment)
•
Always avoid designing airtight battery compart-
ments. In some cases, gases (oxygen, hydro-
gen) may be given off, and there is a danger of
the batteries bursting or rupturing in the presence
of a source of ignition_(sparks generated by a
motor switch, etc.).
6.8 Use of batteries for other purposes
•
Do not use a battery in an appliance or purpose
for which it was not intended. Differences in
specifications can damage the battery or appli-
ance.
Number of Batteries Arranged Serially
1 to 6
(Number of batteries
×
1.0) V
7 to 20
((Number of batteries - 1)
×
1.2) V
5.5 Overdischarge (deep discharge) prevention
•
Overdischarging (deep discharging) or reverse
charging damages the battery characteristics. In
order to prevent damage associated with forget-
ting to turn off the switch or leaving the battery in
the equipment for extended periods, it is hoped
that preventative options are incorporated in the
equipment. At the same time, it is recommended
that leakage current is minimized. Also, the
battery should not be shipped inside the equip-
ment.
6. Prohibited Items Regarding the Battery
Handling
•
Panasonic assumes no responsibility for prob-
lems resulting from batteries handled in the
following manner.
6.1 Disassembly
•
Never disassemble a battery, as the electrolyte
inside is strong alkaline and can damage skin and
clothes.
NICKEL CADMIUM HANDBOOK, PAGE 4
FEBRUARY 2002