Transcript Product Engineering Processes Battery Primer A short battery primer

Product Engineering Processes
Battery Primer
A short battery primer
Handbook of batteries, Linden and Reddy
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Types
Primary (dry cell): non rechargeable
low power applications
infrequent use
Secondary: rechargeable
high discharge rates
frequent use
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Selection considerations
Physical characteristics: size, shape weight
Voltage: nominal, maximum, minimum, discharge profile
Load current: rate, constant power, constant resistance, pulsed
Duty cycle: continuous, intermittent, cyclic
Charge/discharge cycle: cycling (float), deep cycle, efficiency of charging
Temperature range: maximum, minimum and nominal
Service life: required operation time
Safety: failure rates, leakage, off-gassing, toxicity, disposal
Environment: vibration, acceleration, orientation
Maintenance: regular upkeep, replacement
Cost: initial, life-cycle cost
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Cell voltage
Cell voltage
4.5
4
3.5
Voltage (V)
3
2.5
2
1.5
1
0.5
0
Alkaline (p)
Lead- ac id (s)
Nic kel- Cadmium (s)
Battery type
Nic kel- metal
hydride (s)
Lithium- ion (s)
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Specific energy
Specific energy
160
Specific energy (Wh/kg)
140
120
100
80
60
40
20
0
Alkaline (p)
Lead- ac id (s)
Nic kel- Cadmium (s)
Battery type
Nic kel- metal
hydride (s)
Lithium- ion (s)
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Energy density
Energy density
450
400
Energy density (Wh/l)
350
300
250
200
150
100
50
0
Alkaline (p)
Lead- ac id (s)
Nic kel- Cadmium (s)
Battery type
Nic kel- metal
hydride (s)
Lithium- ion (s)
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Self discharge
Shelf life
60
Shelf life (months@20 Celcius)
50
40
30
20
10
0
Alkaline (p)
Lead- ac id (s)
Nic kel- Cadmium (s) Nic kel- metal hydride
(s)
Battery type
Lithium- ion (s)
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Estimated cycle life
Typical cycle life
Typical cycle life (discharge/charge cycles)
1200
1000
800
600
400
200
0
Alkaline (p)
Lead- ac id (s)
Nic kel- Cadmium (s)
Battery type
Nic kel- metal
hydride (s)
Lithium- ion (s)
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Temperature range
Operating temperature
80
Temperature (Celcius)
60
40
20
0
Alkaline (p)
Lead- ac id (s)
Nic kel- Cadmium (s)
- 20
- 40
- 60
Battery type
Nic kel- metal
hydride (s)
Lithium- ion (s)
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Relative cost
Cost
50
45
40
Relative cost/Wh
35
30
25
20
15
10
5
0
Alkaline (p)
Lead- ac id (s)
Nic kel- Cadmium (s) Nic kel- metal hydride
(s)
Battery type
Lithium- ion (s)
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Voltage and state-of-charge
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Temperature and energy density
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Temperature and shelf life
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Power and discharge rate
Watts/litre
1000
100
10
1
Alkaline (p)
Lithium ion (s)
Nickel-metal hydride (s)
0.2
0.1
1
10
100
1000
Nickel-Cadmium (s)
Hours to discharge
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Secondary battery comparison
Lead-acid SLI (starting, lighting, ignition)
advantages
low cost, high availability,
high current, low
temperature, good float
service, maintenance free
Lead-acid traction
lowest cost of deep cycle
systems
Lead-acid stationary
designed specifically for
float charging cycles
maintenance free, long flat
service life, low and high
temperature, operates in
any position
rugged, excellent storage,
high current, low
temperature, operates in
any position
rugged, high energy
density, high current,
operates in any position,
good cycle life
rugged, high energy
density, high specific
energy, operates in any
position, good cycle life, low
self discharge
Lead-acid portable
Nickel-Cadmium (sealed)
Nickel-metal hydride
Lithium ion
disadvantages
Cycle life
low cycle life, shallow
200-700
discharge cycles, low
energy density, poor
charge retention,
hydrogen evolution
low energy density, less 1500
rugged, hydrogen
evolution
hydrogen evolution
Life (years)
4
Cannot be stored
discharged, lower cycle
life, difficult for small
batteries
high cost, memory
effect, poor for float
service
250
8
500
5
high cost (between
Nickel-Cadmium and
Lithium ion)
600
5
lower current, very high 1000+
cost
6
25
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Cycle life and discharge depth (lead-acid)
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Secondary battery charging
Lead-acid
Nickel-Cadmium (sealed)
Nickel-metal hydride
Lithium ion
charge method
current rate C(A) charging energy efficiency
constant current, constant voltage
0.1
75%
constant current
0.3
60%
constant current, constant voltage
0.1
60%
constant current, constant voltage
0.2
95%
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Constant voltage charging (lead-acid)
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Constant current charging (lead-acid)