# Cost of Battery Power

The cost of portable battery power is very expensive when compared to mains power available from a wall receptacle. The typical daily energy consumption of a household is 25 kilowatt-hour (kWh) at a cost of US \$0.05 to 0.10 per kWh. In contrast, the table below shows the cost per kWh using non-rechargeable cells.

 AAA Cell AA Cell C Cell D Cell 9 Volt Capacity 1100mAh 2500mAh 7100mAh 14,300mAh 600mAh Energy 1.4 Wh 3 Wh 9 Wh 18 Wh 4.2 Wh Cost per Cell \$1.25 \$1.00 \$1.60 \$1.60 \$3.10 Cost per KWh \$890 \$330 \$180 \$90 \$730

Note: all costs are in 1998 US \$

The table below compares the cost per KWh when using various types of rechargeable batteries. The cost analysis is based on the purchase cost of the battery and number of discharge-charge cycles it can endure before replacement is necessary, but does not include the electricity needed for charging, nor does it account for the cost of purchasing and maintaining the charging equipment.

 NiCd NiMH SLA Li-ion RAM AA Cell AA Cell typical pack 18650 Cell AA Cell Capacity (mAh) 600 1000 2000 1200 1400 Battery Voltage (V) 7.5 7.5 12 7.2 7.5 Energy per cycle (Wh) 4.5 7.5 24 8.6 6.3 Cycle life 1500 500 250 500 10 Cost per battery \$50 \$70 \$50 \$100 \$6 Cost per KWh \$7.50 \$18.50 \$8.50 \$24.00 \$95.00
• SLA = Sealed Lead Acid

• RAM = Reusable Alkaline Manganese. For the cost calculation of this technology, 840mA is used since all cycles, except for the first one, are rated at 840mA (60% of initial capacity