Product Engineering ProcessesBattery Primer

A short battery primer

Handbook of batteries, Linden and Reddy

Short Primer on BatteriesTypes

Primary (dry cell): non rechargeablelow power applicationsinfrequent use

Secondary: rechargeablehigh discharge ratesfrequent use

Short Primer on BatteriesSelection considerations

Physical characteristics: size, shape weightVoltage: nominal, maximum, minimum, discharge profileLoad current: rate, constant power, constant resistance, pulsedDuty cycle: continuous, intermittent, cyclicCharge/discharge cycle: cycling (float), deep cycle, efficiency of chargingTemperature range: maximum, minimum and nominalService life: required operation timeSafety: failure rates, leakage, off-gassing, toxicity, disposalEnvironment: vibration, acceleration, orientationMaintenance: regular upkeep, replacementCost: initial, life-cycle cost

Short Primer on BatteriesCell voltage

Cell voltage

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

Alkaline (p) Lead-acid (s) Nickel-Cadmium (s) Nickel-metal

hydride (s)

Lithium-ion (s)

Battery type

Vo

ltag

e (

V)

Short Primer on BatteriesSpecific energy

Specific energy

0

20

40

60

80

100

120

140

160

Alkaline (p) Lead-acid (s) Nickel-Cadmium (s) Nickel-metal

hydride (s)

Lithium-ion (s)

Battery type

Sp

ecif

ic e

nerg

y (

Wh

/kg

)

Short Primer on BatteriesEnergy density

Energy density

0

50

100

150

200

250

300

350

400

450

Alkaline (p) Lead-acid (s) Nickel-Cadmium (s) Nickel-metal

hydride (s)

Lithium-ion (s)

Battery type

En

erg

y d

en

sit

y (

Wh

/l)

Short Primer on BatteriesSelf discharge

Shelf life

0

10

20

30

40

50

60

Alkaline (p) Lead-acid (s) Nickel-Cadmium (s) Nickel-metal hydride

(s)

Lithium-ion (s)

Battery type

Sh

elf

lif

e (

mo

nth

s@

20

Celc

ius)

Short Primer on BatteriesEstimated cycle life

Typical cycle life

0

200

400

600

800

1000

1200

Alkaline (p) Lead-acid (s) Nickel-Cadmium (s) Nickel-metal

hydride (s)

Lithium-ion (s)

Battery type

Typ

ical

cycle

lif

e (

dis

ch

arg

e/

ch

arg

e c

ycle

s)

Short Primer on BatteriesTemperature range

Operating temperature

-60

-40

-20

0

20

40

60

80

Alkaline (p) Lead-acid (s) Nickel-Cadmium (s) Nickel-metal

hydride (s)

Lithium-ion (s)

Battery type

Tem

peratu

re (

Celc

ius)

Short Primer on BatteriesRelative cost

Cost

0

5

10

15

20

25

30

35

40

45

50

Alkaline (p) Lead-acid (s) Nickel-Cadmium (s) Nickel-metal hydride

(s)

Lithium-ion (s)

Battery type

Rela

tive c

ost/

Wh

Short Primer on BatteriesVoltage and state-of-charge

Short Primer on BatteriesTemperature and energy density

Short Primer on BatteriesTemperature and shelf life

Short Primer on BatteriesPower and discharge rate

1000

100

10

1

0.20.1 1 10 100 1000

Hours to discharge

Wat

ts/lit

re

Alkaline (p)

Nickel-Cadmium (s)

Nickel-metal hydride (s)Lithium ion (s)

Short Primer on BatteriesSecondary battery comparison

advantages disadvantages Cycle life Life (years)

Lead-acid SLI (starting, lighting, ignition) low cost, high availability, high current, low temperature, good float service, maintenance free

low cycle life, shallow discharge cycles, low energy density, poor charge retention, hydrogen evolution

200-700 4

Lead-acid traction lowest cost of deep cycle systems

low energy density, less rugged, hydrogen evolution

1500 6

Lead-acid stationary designed specifically for float charging cycles

hydrogen evolution 25

Lead-acid portable maintenance free, long flat service life, low and high temperature, operates in any position

Cannot be stored discharged, lower cycle life, difficult for small batteries

250 8

Nickel-Cadmium (sealed) rugged, excellent storage, high current, low temperature, operates in any position

high cost, memory effect, poor for float service

500 5

Nickel-metal hydride rugged, high energy density, high current, operates in any position, good cycle life

high cost (between Nickel-Cadmium and Lithium ion)

600 5

Lithium ion rugged, high energy density, high specific energy, operates in any position, good cycle life, low self discharge

lower current, very high cost

1000+

Short Primer on BatteriesCycle life and discharge depth (lead-acid)

Short Primer on BatteriesSecondary battery charging

charge method current rate C(A) charging energy efficiency

Lead-acid constant current, constant voltage 0.1 75%

Nickel-Cadmium (sealed) constant current 0.3 60%

Nickel-metal hydride constant current, constant voltage 0.1 60%

Lithium ion constant current, constant voltage 0.2 95%

Short Primer on BatteriesConstant voltage charging (lead-acid)

Short Primer on BatteriesConstant current charging (lead-acid)