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RC Battery
Kokam has many kinds of battery solutions not
only for mobile industry but also RC market.
Most of commercial rechargeable batteries cannot support high
rate current drain due to their internal impedance. Normal current
drain for RC application reaches from 5C rate to over 10C rate
in this market. Only some of Ni/Cd rechargeable batteries have
been recognized supporting this high rate condition but they
did not guarantee their cycle life. Recently, some of RC mania
tried to use lithium rechargeable batteries for their RC applications.
They experienced Kokam lithium rechargeable batteries
have high energy density and good high rate capabilities. Especially,
many of RC mania paid attention to one of Kokam
battery SLB452128 is one of the most competitive batteries and
has excellent high rate capability compare to other rechargeable
batteries.
Specification and characteristic of SLB 452128
NO
ITEAMS
SPECIFICATION
REMARK
1
RATED
CAPACITY
Typ.145mAh
(0.2CmA
DISCHARGE)
2
NOMINAL
VOLTAGE
3.7
V
3
CHARGE
CONDITION
Max.
CURRENT
1.0CmA
(130mA)
VOLTAGE
4.2
กพ 0.03 V
4
DISCHARGE
CONDITION
Max.
CURRENT
2.0CmA
(260mA)
Cut-off
Voltage
3.0
V
5
AC
IMPEDANCE
MAX.
120mOHM
At
I kHz
6
CYCLE
LIFE (charge : 0.5CmA,
discharge : 0.5CmA )
500
CYCLES
80%
OF MIN. CAPACITY
7
OPERATING
TEMPERATURE
CHARGE
0
OC ~ 45 OC
DISCHARGE
-20
OC ~ 60 OC
8
DIMENSION
THICKNESS
MAX.
4.80 mm
[FULL CHARGE]
WIDTH
MAX.
21 mm
LENGTH
MAX.
28 mm
9
WEIGHT
3.5
กพ 0.5 g
Similar to other lithium rechargeable batteries, SLB452128
has typical charge discharge characteristics. SLB452128 can
be charged by simple charging process with constant current
at the beginning of the charge cycle and followed by constant
voltage at the end of the charge cycle. However, discharge capacity
of SLB452128 is over 90% of 0.2C capacity even if we discharge
the battery at 2C rate condition. More over some of RC mania
tried to discharge over 10C~15C rates and they have experienced
excellent discharge performance result with no problems during
their operation. Also, Kokam SLB452128 has good
temperature dependent characteristics. It has 58% of capacity
at -20oC compare to ambient temperature and it has 85% of initial
capacity after 500 cycles.
Voltage,
capacity and current vs. time profile of SLB 452128
Rate capability
characteristics of SLB 452128
Discharge profile at various
discharge current Charge : 0.5CmA, CC/CV, 4.2V, 1/20CmA cut-off,
at 23กพ2oC Discharge : Each C-Rate, CC, 3.0V cut-off, at 23กพ2oC
Temperature
dependent characteristics
Discharge profile at various
discharge temperature
after storage 2hrs at each test temperature Charge : 0.5CmA, CC/CV, 4.2V, 1/20CmA CUT-OFF ,
at 23กพ3oC Discharge : 0.5CmA, CC, 3.0V CUT-OFF at VARIOUS
TEMP
Cycle
life characteristics (at ambient temperature)
Charge : 1.0CmA, CC/CV,
4.2V, 1/10CmA CUT-OFF , at 23กพ3oC Discharge : 1.0CmA, CC, 3.0V CUT-OFF , at 23กพ3oC
Another important advantage of SLB452128 is the high rate
charge characteristics.
Many of RC mania have tried to reduce their charging time but
they do not clearly know about effective method. It would be
possible, if RC users know about lithium rechargeable batteries
charging characteristics. Time consuming for charging will reduce
dramatically, if RC users use 90% of battery capacity instead
of 100%. It will reduce more time, if we use 2C or 3C charging
rate. It will only possible when we choose and use the battery
can endure high rate and effectively convert from its electrical
energy to chemical energy at the high current condition. Eaglepicher
Kokam SLB 452128 shows the result its charging time reduce from
80min. to 52min. when we use 1C rate for 90% charging condition.
Also, it shows reducing time from 52min to 36min. when we use
2C or 3C rate for this test.
High rate
charge profile at various charging currents
Charging time depends on charging rate
CHARGE
RATE
CHARGING
TIME(min)
CAPACITY
100%
CAPACITY
90%
CAPACITY
80%
CC
CV
TOTAL
CC
CV
TOTAL
CC
CV
TOTAL
1C
55
25
80
48
4
52
43
0
43
2C
20
58
78
23
13
36
23
5
28
3C
10
67
77
7
7
36
7
18
25
4C
5
70
75
5
5
23
5
11
16
5C
2
73
75
2
2
21
2
13
15
We tried to prove whether SLB452128 shows similar result at
high rate charging-discharging conditions with long cycles.
We was able to observe not so much capacity decay during 100
cycles even we use high rate charge conditions.
Cycle
life characteristics at high rate charge-discharge condition
Charge : Each C-Rate,
CC/CV, Each min cut-off, at 23กพ2oC Discharge : 8.0C(1120mA), CC, 3.0V cut-off, at
23กพ2oC
CHARGE/DISCHARGE
CONDITION
CAPACITY(RATE)
CHARGE
DISCHARGE
1st
CYCLE
50th
CYCLE
100th
CYCLE
RATE
TIME
(min)
CHARGE
DISCHARGE
DISCHARGE
50th/1st(%)
DISCHARGE
100th/1st(%)
1C
-
8C
145.0mAh
(100%)
77.0mAh
(53.1%)
65.3mAh
(45.0%)
84.8
60.0mAh
(41.4%)
77.9
2C
30
8C
123.3mAh
(85%)
67.2mAh
(46.3%)
46.2mAh
(31.9%)
68.8
40.0mAh
(27.6%)
59.5
40
8C
137.8mAh
(95%)
70.7mAh
(48.8%)
50.1mAh
(34.6%)
70.9
45.0mAh
(31.0%)
63.6
3C
20
8C
108.8mAh
(75%)
59.0mAh
(40.7%)
43.6mAh
(30.1%)
73.9
38.6mAh
(26.6%)
65.4
30
8C
127.6mAh
(88%)
60.4mAh
(41.7%)
47.4mAh
(32.7%)
78.5
40.0mAh
(27.6%)
66.2
Normally, high rate performance depends on its power density
therefore we measured and compared some data related power and
energy. Ni/MH and Ni/Cd batteries energy densities do not compete
with lithium batteries' but the power density are superior to
some of lithium polymer batteries at high rate condition over
8C rate. Therefore we can understand some lithium polymer battery
does not show good performance in RC field because of its power
density even though it has high energy density. EaglePicher
Kokam SLB has good power and energy density and shows most reliable
performance for RC mania.
Specification and characteristic of SLB 452128
