 Profile Li-ion
BatteryCharging
Methods of Li-ion Batteries |
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CHARGING METHODS OF Li-ion BATTERIES
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 Li-ion
BATTERY |
|
 Specification
tables |
In
order to ensure the optimal GREENCELL Li-ion battery performance
and safety function,
the following charging method is recommended. |
| Overview |
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| Features |
1.Applicable battery packs |
| Major
applications |
The
battery pack must have a built-in protection module to protect the
Li-ion batteries against
a possible overcharge or over-discharge. The description given below
is for abattery
pack composed of a single cell for reference. |
| Structural
designs |
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| Electrochemical
processes |
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| Characteristics
of Li-ion Batteries |
2.Charging method |
| Charging
methods of Li-ion batteries |
Generally,
higher constant current value for constant current region is thought
to enable
shorten total charging time. But total charging to full-charged
state cannot beshortened
to the degree as it is expected in fact .At the same time, lower
current value
is advantageous to cycle characteristics.However.as battery also
has temperature
depending ability for charging, charging time will become longer,
if charged
at low temperature.Next
the Fig.12 shows general charging flow that we advise for Lithium-ion
battery.At
first, battery temperature is monitored with a thermostat inside
battery pack, and when
it is in the range for charging, voltage of battery pack is checked.
If battery voltage
is less than 3V,it should be preliminary charged at approximately
0.1C. If voltage
becomes more than 3V,then proceed to charge it at 0.5-1C.when current
attenuates
to 0.01-0.05C or less .the charging should be terminated. |
| Electrical
& Mechanical test methods |
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| The
Functions of the Safety Circuits (Typical
Functions) |
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| Precautions
for using Li-ion batteries |
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| Battery
pack specification checklist |
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| Charger
specification checklist |
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| 3.Functions and performance required for Li-ion battery charger | |
| >Charging voltage(charging voltage between the terminals): 4.151-4.249V | |
In
principle, it is desirable to charge the Li-ion batteries at 4.20V.
The tolerance specified
above is provided for variations in equipment, design and fabrication. |
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| >lnitial charging current | |
| Standard charging current: 0.5CmA | |
| Maximum charging current: 1.5CmA | |
| >Charging temperature | |
The
temperature of the Li-ion batteries will rise by approximately 5¡æ
while the batteries
are being charged at stronger current. After switching to the constant-voltage
charge mode, the cell temperature will gradually decrease. |
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| >Low-Voltage Battery Pack Charge | |
When
the voltage per cell is 3.0V or less, charge using a charge current
of 0.1 CmA or less. |
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| >Completion charging | |
Whether
or not the Li-ion battery is fully charged should be determined
by detecting the
charging current. A detected current of 0.1 CmA indicates that the
battery is charged
to 93% or 94% of its capacity. |
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| >Protection features | |
If
the charging voltage exceeds 4.2V,the charging should be completed.If
the battery voltage remains at less than 3.0V for a specified duration
of time in the trickle-charging
mode during battery check, the battery should be deemed abnormal
and
charging should be avoided.The
Li-ion battery has characteristics that allow for trickle charging
within the temperature
range from 0 to 45
celsius . however, it is recommendable to provide the timer
for the safety purposes. |
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| >Countermeasure for abnormalities in power supply unit | |
To
prevent an over-voltage to the battery in the event of a malfunction
in the power supply
unit, select the unit equipped with over-voltage protection. |
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Fig.12
Lithium Ion Battery Pack Charge Flow Chart(Reference) |
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