Internet of Things: Batteries A Short Review Dr. Eng. Amr T. Abdel-Hamid NETW 1010 Fall 2013

Dr. Amr Talaat NETW 1010 Internet of Things E radio Calculations E radio = (P(per Bit)* Number of Bits)+ (I sleep * V * T) Total Energy used for this module What kind of a battery needed then?!

Dr. Amr Talaat NETW 1010 Internet of Things Battery (Short Review) Duracell batteries6v dry cell9v battery More precisely Two cellsA real batteryAnother battery

Dr. Amr Talaat NETW 1010 Internet of Things Batteries  Cheap  Easy to use  Rechargeable batteries available  Lithium Ion batteries with high capacity  Charging is simple and easy  Size of batteries is a problem  AA battery defines the size of many devices  Environment (temperature) has influence on the capacit y

Dr. Amr Talaat NETW 1010 Internet of Things Battery Characteristics  Size  Physical: button, AAA, AA, C, D,...  Energy density (watts per gram or cm 3 )  Longevity  Capacity (Ah, for drain of C/10 at 20°C)  Number of recharge cycles  Discharge characteristics (voltage drop)

Dr. Amr Talaat NETW 1010 Internet of Things Further Characteristics  Cost  Behavioral factors  Temperature range (storage, operation)  Self discharge  Memory effect  Environmental factors  Leakage, gassing, toxicity  Shock resistance

Dr. Amr Talaat NETW 1010 Internet of Things Battery Organization

Dr. Amr Talaat NETW 1010 Internet of Things Battery Connections

Dr. Amr Talaat NETW 1010 Internet of Things Primary (Disposable) Batteries  Zinc carbon (flashlights, toys)  Heavy duty zinc chloride (radios, recorders)  Alkaline (all of the above)  Lithium (photoflash)  Silver, mercury oxide (hearing aid, watches)  Zinc air

Dr. Amr Talaat NETW 1010 Internet of Things Alkaline Battery Discharge

Dr. Amr Talaat NETW 1010 Internet of Things Secondary (Rechargeable) Batteries  Nickel cadmium  Nickel metal hydride  Alkaline  Lithium ion  Lithium ion polymer  Lead acid

Dr. Amr Talaat NETW 1010 Internet of Things Nickel Cadmium Batteries  Chemistry Cadmium (-), nickel hydroxide (+) Potassium hydroxide aqueous electrolyte  Features +Rugged, long life, economical +Good high discharge rate (for power tools)  Relatively low energy density  Toxic

Dr. Amr Talaat NETW 1010 Internet of Things NiCd Recharging  Over 1000 cycles (if properly maintained)  Fast, simple charge (even after long storage) C/3 to 4C with temperature monitoring  Self discharge 10% in first day, then 10%/mo Trickle charge (C/16) will maintain charge  Memory effect (Medium Effect over time)

Dr. Amr Talaat NETW 1010 Internet of Things NiCd Memory Effect

Dr. Amr Talaat NETW 1010 Internet of Things NiMH Battery Discharge

Dr. Amr Talaat NETW 1010 Internet of Things NiMH Recharging  Less prone to memory than NiCd  Shallow discharge better than deep Degrades after deep cycles Need regular full discharge to avoid crystals  Self discharge more than NiCd  Longer charge time than for NiCd To avoid overheating

Dr. Amr Talaat NETW 1010 Internet of Things NiCd v NiMH Self-Discharge

Dr. Amr Talaat NETW 1010 Internet of Things Secondary Alkaline Batteries  Features  50 cycles at 50% discharge  No memory effect  Shallow discharge better than deeper

Dr. Amr Talaat NETW 1010 Internet of Things NiCd v Alkaline Discharge

Dr. Amr Talaat NETW 1010 Internet of Things Lithium Ion Batteries  Chemistry Graphite (-), cobalt or manganese (+) Nonaqueous electrolyte  Features +40% more capacity than NiCd +Flat discharge (like NiCd) +Self-discharge 50% less than NiCd  Expensive

Dr. Amr Talaat NETW 1010 Internet of Things Lithium Ion Recharging  300 cycles  50% capacity at 500 cycles

Dr. Amr Talaat NETW 1010 Internet of Things Lithium Ion Polymer Batteries  Chemistry Graphite (-), cobalt or manganese (+) Nonaqueous electrolyte  Features +Slim geometry, flexible shape, light weight +Potentially lower cost (but currently expensive) +Higher discharge  Lower energy density, fewer cycles than Li-ion

Dr. Amr Talaat NETW 1010 Internet of Things Battery Capacity TypeCapacity (mAh) Density (mWh/g) Alkaline AA Rechargeable NiCd AA75041 NiMH AA Lithium ion Lead acid200030

Dr. Amr Talaat NETW 1010 Internet of Things Discharge Rates TypeVoltagePeak Drain Optimal Drain Alkaline1.50.5C< 0.2C NiCd1.2520C1C Nickel metal1.255C< 0.5C Lead acid25C0.2C Lithium ion3.62C< 1C

Dr. Amr Talaat NETW 1010 Internet of Things Recharging TypeCycles (to 80%) Charge time Discharge per month Cost per kWh Alkaline50 (50%)3-10h0.3%$95.00 NiCd15001h20%$7.50 NiMH h30%$18.50 Li-ion h10%$24.00 Polymer h10% Lead acid h5%$8.50

Dr. Amr Talaat NETW 1010 Internet of Things Energy harvesting  Capacity of battery limits the lifetime of the device  Battery depletion -> Device cannot work -> (Sensor) network cann ot work  Idea: recharge the batteries during operation  Use energy from the environment  Current approaches  Photovoltaics: Solar modules for sensor nodes  Thermoelectric generators  Conversion of temperature differences to energy  Kinetic energy conversion  Piezo-electric principle already tested for shoes  MEMS gas turbines  Convert air- or fluid streams