Xantrex DR1512W, Installation And Operation Manual, Page: 97 / 122

Battery Bank Sizing
975-0012-01-02 Rev A B–7
Battery bank size worksheet
Calculation To calculate the battery bank size, use the average amp-hours per day that you
calculated using Table B-1, then make the other calculation shown in Table B-2 to
calculate the battery bank size you need to support your loads.
Worksheets Table B-1 and Table B-2 are examples only. Use the specifications noted on the
label of each AC appliance and fill in the values specific for the appliances used in
this installation on the a work sheet.
Table B-3 provides a typical wattage for selected appliances. However, you
should try to find the exact wattage on the appliance label.
Table B-2 Determining Battery Bank Size
Average amp hours per day 95
Divided by inverter efficiency (90%) for DR Inverter 0.9
Divided by battery efficiency (usually 0.75) 0.75
Adjusted hours per day 140
Divided by Depth of Discharge (usually 60%) 0.6
Multiplied by days of autonomy 5
Battery bank size required 1173 Ah
Table B-3 Typical Appliance Wattage
Appliance Watts Appliance Watts
Fluorescent Type Light 10 Blender 400
Computer 200-300 Toaster 1000
Microwave (compact) 600-800 Hot Plate 1800
Microwave (full-size) 1500 Washer/Dryer 375-1000
Stereo or VCR 50 3/8" Drill 500
Color Television (19") 150 Hair Dryer or Iron 1000
Refrigerator (3 cu ft) 180 Vacuum Cleaner 1200
Refrigerator (12 cu ft) 480 Coffee Maker 1200