 Profile Ni-MH
BatteryPrecautions
for Using Ni-MH Batteries |
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PRECAUTIONS
FOR USING Ni-MH BATTERIES
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 Ni-MH
BATTERY |
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 Specification
tables |
In
order to take full advantage of the properties of GREENCELL Ni-MH
batteries` characteristics
in use and in the design of battery-operated, and also to prevent
problems
due to improper use, please pay proper attention to the following
points. |
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| Overview |
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| Features |
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| Comparison
of Ni-MH and Ni-Cd Cells |
1. Charging | ||||
| Major
applications |
Charging Temperature | ||||
| Structural
designs |
>Charge batteries within an ambient temperature range of 0 to 40 celsius. | ||||
| Electrochemical
processes |
>Ambient
temperature during charging affects charging efficiency. As charging
efficiency
is best within a temperature range of 10 to 30 celsius, whenever
possible place
the charger (battery pack) in a location within this temperature
range. |
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| Discharge
characteristics |
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| Charge
characteristics |
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| Charging
methods |
>At
temperatures below celsius the gas absorption reaction is not adequate,
causing
gas of pressure inside the battery to rise, which can activate the
safety vent and
lead to leakage alkaline gas and deterioration in battery performance. |
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| Cycle
life characteristics |
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| Storage
characteristics |
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| Safety
characteristics |
>Charging
efficiency drops at temperatures above 45 celsius. This can disrupt
full charging
and lead to deterioration in performance and battery leakage. |
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| Designing
for Ni-MH cells |
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| Battey
pack designs |
Parallel charging of batteries(Don`t try to parallel charge!) | ||||
| Battery
pack configurations designation system |
Sufficient
care must be taken during the design of the charger when charging
batteries
connected in parallel. Consult we when parallel charging is required. |
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| Precautions
for using Ni-MH batteries |
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| Battery
selection |
Reverse charging(Never reverse charge!!!) | ||||
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. |
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| Overcharging(Avoid overcharging!) | |||||
Repeated
overcharging can lead to deterioration in battery performance.g("Overcharging"
means charging a battery when it is already fully charged.) |
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| Rapid charging | |||||
To
charge batteries rapidly, use the specified charger (or charging
method recommended
by us and follow the correct procedures). |
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| Trickle charging (continuous charging) | |||||
Carry
out trickle charge by applying the current of 1/30 to 1/20 CmA.
The correct current
value is determined depending on the features and purpose of the
equipment. |
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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¡Á1500, or roughly 50mA. |
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| 2. Discharging | |||||
| Discharge Temperature | |||||
| >Discharge batteries within an ambient temperature range of -10 to +50 ceslius. | |||||
>Discharge
current level (i. e. the current at which a battery is discharged)
affectsdischarging
efficiency. Discharging efficiency is good within a current range
of 0.1
CmA to 2 CmA. |
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>Discharge
capacity drops at temperatures below -10 or above +45 celsius. Such
decreases
in discharge capacity can lead to deterioration in battery performance. |
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| Overdischarge (Deep Discharge) | |||||
Since
overdischarging (deep discharge) 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 a prolonged periods.Besides, avoid shipping
the battery
installed in the equipment. |
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| High-rate discharging | |||||
As
high-rate discharging can generate a lot of heat and decreased discharging
efficiency,
please consult us before attempting continuous discharging or pulse
discharging
at currents larger than 2 CmA. |
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| 3. Storage | |||||
| Short-term Storage temperature and humidity | |||||
>Store
batteries in a dry location with low humidity, no corrosive gases,
and at a temperature
range of -20 to +45 celsius. |
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>Storing
batteries in a location where humidity is extremely high or where
temperatures
fall below -20 or rise above +45 celsius can lead to the rusting
of metallic
parts and battery leakage due to expansion or contraction in parts
composed
of organic materials. |
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| Long-term storage (1 year, -20 to +35 celsius) | |||||
>Because
long-term storage can accelerate battery self-discharge and lead
to the +30
celsius are deactivation of reactants, locations where the temperature
ranges between
+10 celsius and suitable for long-term storage. |
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>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
tooriginal performance by repeating several cycles of charging and
discharging. |
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>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
charge if voltage detection type, carry out charge and discharge
at least once every
6 months. |
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| 4. Service Life of Batteries | |||||
| Cycle life | |||||
Batteries
used under proper conditions of charging and discharging can be
used 500 the
cycles or more. Significantly reduced service time in spite of proper
charging means
that life of the battery has been exceeded. Also, at the end of
service life, an unusal
increase 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. |
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| Service life with long-term use | |||||
Because
batteries are chemical products involving internal chemical reactions,
performance
deteriorates not only with use but also during prolonged storage.
Normally,
a battery will last 3 to 5 years (or 500 cycles) 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 deterioration
in performance due to leakage and shortened service life. |
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| 5. Design of Products Which Use Batteries | |||||
| 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, separator, and
other parts made
of organic materials. |
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>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. |
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>Use
caution in applying pressure to the terminals in cases where the
battery pack can
be separated from the equipment. |
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| Material for terminals in products using the batteries | |||||
Because
small amounts of alkaline electrolyte can leak from the battery
seal during extended
use or when the safety vent is activated during improper use, a
highly alkaline-resistant
material should be used for a product's contact terminals in order
to
avoid problems due to corrosion. |
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| (Note: that stainless steel generally results in higher contact resistance.) | |||||
| Temperature related the position of batteries in products | |||||
As
excessively high temperatures (i.e. more than 45¡æ)
can cause alkaline electrolyte
to is 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 the product. The best battery
position is in a
battery compartment that circuitry. This prevents damage that may
be caused by a
slight leakage of alkaline electrolyte from the battery. Be careful
particularly when trickle
charge is carried out(for contions charge). |
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| Discharge end voltage | |||||
The
discharge end voltage is determined by the formula given below.
Please set the end
voltage of each battery at 1.1 volts or less.Number
of batterries arranged serially: |
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| Overdischarge (deep discharge) prevention | |||||
Overdischarging
(deep discharging) or reverse charging damages the battery or leaving
characteristics. In order to prevent damage associated with forgetting
to turn off
the switch the battery in the equipment for extended periods, it
is hoped that preventative
options should be incorporated in the equipment. At the same time,
it is recommended
that leak-age current is minimized. Besides, the battery should
not be
shipped inside the equipment. |
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| 6. Prohibited Items Regarding the Battery Handling | |||||
We
assumes no responsibility for problems resulting from batteries
handled in the following
manner. |
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| A. Disassembly | |||||
Never
disassemble a battery, as the electrolyte inside is strong alkaline
and can damage
skin and clothes. |
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| B. Short-circuiting | |||||
Never
attempt to short-circuit a battery. Doing so can damage the product
and generate
heat that can cause burns. |
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| C. 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. | |||||
| D. 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. |
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| E. Inserting the batteries with their polarities reversed | |||||
Never
insert a battery with the positive and negative poles reversed.
as this can cause
the battery to swell or rupture. |
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| F. Overcharging at high currents and reverse charging | |||||
>Never
reverse charge or overcharge with high currents (i.e. more than
rated). Doing so
causes rapid gas generation and increased gas pressure, thus
causing batteries to
swell or rupture. |
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>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 instructions as a handling restriction for ensuring
safety. |
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| G. Installation in equipment (with a sealed construction) | |||||
Always
avoid designing airtight battery compartments. In some cases, gases
(oxygen,
the hydrogen) may be given off, and there is a danger of the batteries
bursting
or rupturing in presence of a source of ignition (sparks generated
by a motor switch,
etc.). |
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| H. 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 appliance. |
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| I. Short-circuiting of battery packs | |||||
Special
caution is required to prevent short-circuits.Because of product
or battery shape,
in case battery packs that are used as insertion to equipment may
be inserted
in reverse. And also, caution must be given to certain structures,
which, depending
on product terminal shape. |
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| J. Using old and new batteries together | |||||
Avoid
using old and new batteries together. Also avoid using these batteries
with ordinary
dry-cell batteries, Ni-Cd batteries or with another manufacturer's
batteries.ordinary
dry-cell batteries, Ni-Cd batteries or with another manufacturer's
batteries.Differences
in various characteristic values, etc.,can cause damage to batteries
or the
product. |
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| 7. Other Precautions | |||||
| >Batteries should always be charged prior to use. Be sure to charge correctly. | |||||
>In
order to ensure safe battery use and to prolong the battery performance,
please the
consult us regarding charge and discharge conditions for use and
product design prior
to release of a battery-operated product. |
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>A
rechargeable battery is delivered without charge, so its voltage
may be lower than
1.2V. It will recover to normal level after a charge cycle. |
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>Before
the test or use, batteries shall be discharged because they may
have some residual
capacity. |
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| >Do not swallow batteries. | |||||
