Xantrex Technology 120 VAC/60 owner manual Worksheet, 103

TECHNICAL INFORMATION

WORKSHEET

Complete the steps that follow to calculate your inverter’s battery bank capacity.

STEP 1-4:Determine your Average Daily Watt Hours Needed.

	STEP 1	STEP 2	STEP 3
AC APPLIANCE	APPLIANCE RUNNING	(X) HOURS USED	(X) DAYS USED
	WATTS	EACH DAY	EACH WEEK

STEP 4

(⎟ 7 = ) AVERAGE DAILY

WATT HOURS NEEDED

STEP 1: Determine what appliances the inverter will power and enter the Appliance Running Wattage of each appliance.

STEP 2: Determine the number of hours (or fractions of hours) you will use the appliance each day;

STEP 3: Multiply the number of days you will use the appliance during the week; this is your Weekly Watt Hours Needed;

STEP 4: Divide your Weekly Watt Hours Needed by 7 to obtain the Average Daily Watt-Hours Needed;

STEP 5: Total Average Daily Watt Hours Needed to determine your Total Daily Watt Hours Needed.

Total Daily Watt-Hours Needed

. .

STEP 6: Multiply your Total Daily Watt Hours Needed (Step 5) by the number of anticipated days of autonomy (days between charging, usually 1 to 5) to determine your Autonomy Battery Size (example used 3 days).

STEP 7: Multiply your Autonomy Battery Size (Step 6) x 2 to allow for a 50% maximum battery discharge in normal operation and an additional 50% for emergency situations to obtain your Rough Battery Size in watt hours.

Autonomy Battery Size

(Watt Hours)

. .

Rough Battery Size (Watt-Hours)

. .

STEP 8: Multiply your Rough Battery Estimate x 1.2 to allow for an efficiency of 80%. This number is your Safe Battery Size in watt-hours.

STEP 9: Convert your Safe Battery Size to amp-hours. Divide Safe Battery Size by the DC system voltage (i.e., 12, 24 or 48 VDC; example used

24 volts). This number is your Safe Battery Size in amp hours, which is the battery bank capacity needed before recharging.

Safe Battery Size (Watt-Hours)

. .

Safe Battery Size (Amp-Hours)

. .

 2001 Xantrex Technology, Inc.	Telephone: 360/435-8826	SW Series Inverter/Charger
5916 - 195th Street N. E.	Fax: 360/435-2229	Part No. 2031-5
Arlington, WA 98223	www.traceengineering.com	Rev. C: February 2001

Page

103