Xantrex DR1512E - Page 67

5.0 APPENDIX
59
©2000 Xantrex Technology Inc.
Step 8 Multiply the AUTONOMY BATTERY SIZE (Step 7) figure by 2 to provide a 50%
maximum battery discharge level. Enter this figure in the ROUGH BATTERY SIZE
(WATT-HOURS) (Step 8) column.
Step 9 Multiply the ROUGH BATTERY SIZE (WATT-HOURS) figure (Step 8) by 1.2 and enter
this figure in the SAFE BATTERY SIZE (WATT-HOURS) (Step 9) column. This figure
allows for an efficiency of 80%.
Step 10 Divide the SAFE BATTERY SIZE (WATT-HOURS) (Step 9) figure by the DC system
voltage (i.e., 12, 24 or 48 volts). Enter this number in the SAFE BATTERY SIZE (AMP-
HOURS) (Step 10) column. Use this figure to determine the number of batteries
required to reach the amp-hour rating.
Step 1
AC Appliance
Step 2 Step3 Step 4 Step 5
Appliance
Running
Watts
(x) Hours Used
Each Day
(x) Days Used
Each Week
(÷ 7 =) Average Daily
Watt-Hours Required
Step 6
Total Daily Watt-Hours
Required
Step 7
Autonomy
Battery Size
Step 8
Rough Battery Size
(Watt-Hours)
Step 9
Safe Battery Size
(Watt-Hours)
Step 10
Safe Battery Size
(Amp-Hours)
975-0012-017