Xantrex Technology SW Plus 4024 - Manual (Page 297)

Battery Bank Sizing
976-0043-01-02 C–7
Amp Hour Example Worksheet
Complete the following steps to calculate the amp-hour requirements per
day for your system. Use and
Table C-2 as examples to complete your
own.
To calculate amp-hour requirements:
1. Determine the loads the inverter will power and enter their wattage in
the watts column.
2. Determine the number of hours (or decimal portion of hours) the
appliance is used each day. Enter this figure in the Hours column.
3. Determine the number of days the appliance will be used during the
week. Enter this figure in the Days column.
4. Multiply Hours x Days for each load identified to determine the watt/
hours per week.
5. Add the total watt/hours per week for all loads then divide by 7 to
obtain the average total watt/hours per day.
6. Divide the total average per day by the DC nominal voltage.
This figure represents the average amp-hours per day that you will
use.
Table C-1 Determining Average Daily Load in Amp-hours
Load Watts Hours per Day
Days per
week used Weekly
watt-hours
5 lights: 15 W CFL 75 W 5 7 2625
Breadmaker 1200 0.75 2 1800
Energy-efficient
refrigerator 200 x 0.3 24 10080
Laptop computer 50 6 5 1500
Total weekly watt-hours of AC load 16005 Wh
Divided by days per week 7
Average total watt-hours per day 2286
Divided by DC nominal voltage 24
Average amp-hours per day (Ah/d) 95