Product Engineering Processes Battery Primer A short battery primer Handbook of batteries, Linden and Reddy
Types Primary (dry cell): non rechargeable low power applications infrequent use Secondary: rechargeable high discharge rates frequent use
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
Cell voltage Cell voltage 4.5 4 3.5 3 Voltage (V) 2.5 2 1.5 1 0.5 0 Alkaline (p) Lead-acid (s) Nickel-Cadmium (s) Nickel-metal hydride (s) Battery type Lithium-ion (s)
Specific energy Specific energy 160 140 Specific energy (Wh/kg) 120 100 80 60 40 20 0 Alkaline (p) Lead-acid (s) Nickel-Cadmium (s) Nickel-metal hydride (s) Battery type Lithium-ion (s)
Energy density Energy density 450 400 350 Energy density (Wh/l) 300 250 200 150 100 50 0 Alkaline (p) Lead-acid (s) Nickel-Cadmium (s) Nickel-metal hydride (s) Battery type Lithium-ion (s)
Self discharge Shelf life 60 Shelf life (months@20 Celcius) 50 40 30 20 10 0 Alkaline (p) Lead-acid (s) Nickel-Cadmium (s) Nickel-metal hydride (s) Battery type Lithium-ion (s)
Estimated cycle life Typical cycle life 1200 Typical cycle life (discharge/charge cycles) 1000 800 600 400 200 0 Alkaline (p) Lead-acid (s) Nickel-Cadmium (s) Nickel-metal hydride (s) Battery type Lithium-ion (s)
Temperature range Operating temperature 80 60 Temperature (Celcius) 40 20 0-20 Alkaline (p) Lead-acid (s) Nickel-Cadmium (s) Nickel-metal hydride (s) Lithium-ion (s) -40-60 Battery type
Relative cost Cost Relative cost/wh 50 45 40 35 30 25 20 15 10 5 0 Alkaline (p) Lead-acid (s) Nickel-Cadmium (s) Nickel-metal hydride (s) Battery type Lithium-ion (s)
Voltage and state-of-charge
Temperature and energy density
Temperature and shelf life
Power and discharge rate 1000 Watts/litre 100 10 1 0.2 Nickel-metal hydride (s) 0.1 1 10 100 1000 Nickel-Cadmium (s) Hours to discharge Alkaline (p) Lithium ion (s)
Secondary battery comparison Lead-acid SLI (starting, lighting, ignition) Lead-acid traction Lead-acid stationary Lead-acid portable Nickel-Cadmium (sealed) Nickel-metal hydride Lithium ion advantages disadvantages Cycle life Life (years) low cost, high availability, low cycle life, shallow 200-700 4 high current, low discharge cycles, low temperature, good float energy density, poor service, maintenance free charge retention, lowest cost of deep cycle systems 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 hydrogen evolution low energy density, less rugged, hydrogen evolution 1500 6 hydrogen evolution 25 Cannot be stored discharged, lower cycle life, difficult for small batteries high cost, memory effect, poor for float service high cost (between Nickel-Cadmium and Lithium ion) lower current, very high cost 250 8 500 5 600 5 1000+
Cycle life and discharge depth (lead-acid)
Secondary 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%
Constant voltage charging (lead-acid)
Constant current charging (lead-acid)