04-05-2012, 05:27 PM
Battery Overview
[attachment=21322]
Motivation
To exploit properties of batteries in low-power designs
Protocols (Span , MAC layer)
Hardware (Cricket)
Example: n cells; discharge from each cell, round-robin fashion [Chiasserini and Rao, INFOCOM 2000]
Battery Characteristics
Size
Physical: button, AAA, AA, C, D, ...
Energy density (watts per kg or cm3)
Longevity
Capacity (Ah, for drain of C/10 at 20°C)
Number of recharge cycles
Discharge characteristics (voltage drop)
Further Characteristics
Cost
Behavioral factors
Temperature range (storage, operation)
Self discharge
Memory effect
Environmental factors
Leakage, gassing, toxicity
Shock resistance
Standard Zinc Carbon Batteries
Chemistry
Zinc (-), manganese dioxide (+)
Zinc, ammonium chloride aqueous electrolyte
Features
Inexpensive, widely available
Inefficient at high current drain
Poor discharge curve (sloping)
Poor performance at low temperatures
[attachment=21322]
Motivation
To exploit properties of batteries in low-power designs
Protocols (Span , MAC layer)
Hardware (Cricket)
Example: n cells; discharge from each cell, round-robin fashion [Chiasserini and Rao, INFOCOM 2000]
Battery Characteristics
Size
Physical: button, AAA, AA, C, D, ...
Energy density (watts per kg or cm3)
Longevity
Capacity (Ah, for drain of C/10 at 20°C)
Number of recharge cycles
Discharge characteristics (voltage drop)
Further Characteristics
Cost
Behavioral factors
Temperature range (storage, operation)
Self discharge
Memory effect
Environmental factors
Leakage, gassing, toxicity
Shock resistance
Standard Zinc Carbon Batteries
Chemistry
Zinc (-), manganese dioxide (+)
Zinc, ammonium chloride aqueous electrolyte
Features
Inexpensive, widely available
Inefficient at high current drain
Poor discharge curve (sloping)
Poor performance at low temperatures