Solar Power
Battery Power

Charge Time vs. Charge Voltage	Characteristic Discharge Curves
Cycle Life vs. Depth of Discharge	Shelf Life vs. Storage Temperature
Effect of Temperature on Capacity	Charging Temperature Voltage Compensation
Temperature Range Summary	RECHARGEABLE BATTERY PACK COMPARISON

RECHARGEABLE BATTERY PACK COMPARISON
ELECTROCHEMISTRY	UNITS	SEALED LEAD-ACID	IPC THINLINE	NICKEL CADMIUM	NICKEL M/HYDRIDE	LITHIUM ION
NOMINAL CELL VOLTAGE	VPC	2	2	1.2	1.2	3.7
FORM FACTOR	-	ALL	PLANAR CELL	ALL	ALL	ALL
ENERGY DENSITY (BATTERY PACK) GRAVIMETRIC (SPECIFIC ENERGY) VOLUMETRIC (ENERGY DENSITY)	Wh/kg Wh/l	35 80	44 111	41 94	52 135	100 196
DISCHARGE CURVE FUEL GAUGE CAPABILITY (VOLTAGE) FUEL GAUGE CAPABILITY (Ah IN/OUT)	%C %C	SLOPING GOOD GOOD	SLOPING GOOD GOOD	FLAT POOR MEMORY	FLAT POOR MEMORY	SLOPING GOOD GOOD
MEMORY EFFECTS LIFE EFFECTS OF CHARGE/DISCHARGE	YEARS	NONE MINIMAL	NONE MINIMAL	YES SIGNIFICANT	YES SIGNIFICANT	DELAY SIGNIFICANT
ENVIRONMENTAL CONCERNS RECYLABILITY	%	Pb >95	Pb >95	Ni/Cd 0-90	Ni/Rare EARTHS 0-50	Co/Ni 0
SAFETY OVERCHARGE PROTECTION LEVELS OVERDISCHARGE PROTECTION LEVELS	# #	PROVEN 2 1	PROVEN 2 0	PROVEN 2 0	PROVEN 2 0	DOUBTS 5 2
PACK CIRCUITRY REQUIREMENTS CHARGE CONTROL LEVELS DISCHARGE CONTROL LEVELS THERMAL PROTECTION OTHER (pressure, over-current,etc)	# # # #	2 1 1 0	2 0 0 0	1 0 1 1	2 0 1 1	2 2 1+ 3
CYCLE LIFE (to 80% of rated capacity) 25% DOD @ C/5-2 cycles/day 50% DOD @ C/5-2 cycles/day 100% DOD @ C/5-2 cycles/day ** Restricted because of safety issues	Cycles Cycles Cycles	1200 600 300	2000 1000 500	2000 1000 500	500 500 300	500 350 **